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This '''glossary of mechanical engineering terms''' pertains specifically to [[mechanical engineering]] and its sub-disciplines. For a broad overview of engineering, see [[glossary of engineering]].

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==A==
*'''[[Abrasion (mechanical)|Abrasion]]''' – is the process of scuffing, scratching, wearing down, marring, or rubbing away.  It can be intentionally imposed in a controlled process using an abrasive. Abrasion can be an undesirable effect of exposure to normal use or exposure to the elements. 
*'''[[Absolute zero]]''' – is the lowest possible [[temperature]] of a system, defined as zero [[kelvin]] or −273.15 °C. No experiment has yet measured a temperature of absolute zero.
*'''[[Accelerated life testing]]''' – is the process of testing a product by subjecting it to conditions ([[Stress (mechanics)|stress]], [[Strain (mechanics)|strain]], temperatures, voltage, vibration rate, pressure etc.) in excess of its normal service parameters in an effort to uncover faults and potential modes of failure in a short amount of time.<ref>{{Cite journal | last1 = Nelson | first1 = W. | volume=R-29 |  doi = 10.1109/TR.1980.5220742 | title = Accelerated Life Testing - Step-Stress Models and Data Analyses | journal = IEEE Transactions on Reliability | issue = 2 | page = 103 | year = 1980 | s2cid = 35734439 }}</ref><ref>{{Cite journal | last1 = Spencer | first1 = F. W. | title = Statistical Methods in Accelerated Life Testing | doi = 10.1080/00401706.1991.10484846 | journal = [[Technometrics]] | volume = 33 | issue = 3 | pages = 360–362 | year = 1991 }}</ref> By analyzing the product's response to such tests, [[engineer]]s can make predictions about the service life and maintenance intervals of a product.<ref>{{Cite book | last1 = Donahoe | first1 = D. | last2 = Zhao | first2 = K. | last3 = Murray | first3 = S. | last4 = Ray | first4 = R. M. | chapter = Accelerated Life Testing | doi = 10.1002/9780470061596.risk0452 | title = Encyclopedia of Quantitative Risk Analysis and Assessment | year = 2008 | isbn = 9780470035498 | s2cid = 86534403 }}</ref><ref>{{Cite book | last1 = Elsayed | first1 = E. A. | chapter = Accelerated Life Testing | doi = 10.1007/1-85233-841-5_22 | title = Handbook of Reliability Engineering | pages = 415–428 | year = 2003 | isbn = 1-85233-453-3 }}</ref>
*'''[[Acceleration]]''' – In [[physics]], ''acceleration'' is the [[Rate (mathematics)|rate]] of change of [[velocity]] of an object with respect to time. An object's acceleration is the net result of any and all [[force]]s acting on the object, as described by [[Newton's Second Law]].<ref>{{cite book |title=The Principles of Mechanics |first=Henry |last=Crew |publisher=BiblioBazaar, LLC |year=2008 |isbn=978-0-559-36871-4 |pages=43}}</ref> The [[International System of Units|SI]] unit for acceleration is [[metre per second squared]] {{nowrap|(m s<sup>−2</sup>).}} Accelerations are [[Euclidean vector|vector]] quantities (they have [[Magnitude (mathematics)|magnitude]] and [[Direction (geometry)|direction]]) and add according to the [[parallelogram law]].<ref>{{cite book |title=Relativity and Common Sense |first=Hermann |last=Bondi |pages=[https://archive.org/details/relativitycommon0000bond/page/3 3] |publisher=Courier Dover Publications |year=1980 |isbn=978-0-486-24021-3 |url=https://archive.org/details/relativitycommon0000bond/page/3 }}</ref><ref>{{cite book |title=Physics the Easy Way |pages=[https://archive.org/details/physicseasyway00lehr_0/page/27 27] |first=Robert L. |last=Lehrman |publisher=Barron's Educational Series |year=1998 |isbn=978-0-7641-0236-3 |url=https://archive.org/details/physicseasyway00lehr_0/page/27 }}</ref>  As a [[Vector space|vector]], the calculated net [[force]] is equal to the product of the object's mass (a [[Scalar (physics)|scalar]] quantity) and its acceleration.
*'''[[Accelerometer]]''' – is a device that measures [[proper acceleration]].<ref name="Tinder">{{cite book |title=Relativistic Flight Mechanics and Space Travel: A Primer for Students, Engineers and Scientists |first1=Richard F. |last1=Tinder |publisher=Morgan & Claypool Publishers |year=2007 |isbn=978-1-59829-130-8 |page=33 }} [https://books.google.com/books?id=-uMRwLaNbC8C&pg=PA33 Extract of page 33]</ref> Proper acceleration, being the [[acceleration]] (or [[rate of change (mathematics)|rate of change]] of [[velocity]]) of a body in its own instantaneous [[rest frame]],<ref name="Rindler">{{cite book |title=Essential Relativity: Special, General, and Cosmological |edition=illustrated |first1=W. |last1=Rindler |publisher=Springer |year=2013 |isbn=978-1-4757-1135-6 |page=61 |url=https://books.google.com/books?id=WTfnBwAAQBAJ}} [https://books.google.com/books?id=WTfnBwAAQBAJ&pg=PA61 Extract of page 61]</ref> is not the same as coordinate acceleration, being the acceleration in a fixed [[coordinate system]]. 
*'''[[Accuracy and precision]]''' – In measurement of a set, ''accuracy'' is closeness of the measurements to a specific value, while ''precision'' is the closeness of the measurements to each other. More commonly, accuracy or ''trueness'' is a description of ''[[systematic errors]]'', a measure of [[statistical bias]], while precision is a description of ''[[random errors]]'', a measure of [[statistical variability]]; the two concepts are independent of each other. Alternatively, [[International Organization for Standardization|ISO]] defines<ref name="iso5725">BS ISO 5725-1: "Accuracy (trueness and precision) of measurement methods and results - Part 1: General principles and definitions.", p.1 (1994)</ref> accuracy as describing a combination of both random and systematic [[observational error]], so high accuracy requires both high precision and high trueness.
*'''[[Ackermann steering geometry]]''' – a geometric arrangement of linkages in the [[steering]] of a car or other vehicle designed to solve the problem of wheels on the inside and outside of a turn needing to trace out circles of different [[radius|radii]]. It was invented by the German carriage builder [[Georg Lankensperger]] in Munich in 1817, then patented by his agent in England, [[Rudolph Ackermann]] (1764–1834) in 1818 for horse-drawn carriages. [[Erasmus Darwin]] may have a prior claim as the inventor dating from 1758.<ref>[https://www.jstor.org/pss/532121 Erasmus Darwin's Improved Design for Steering Carriages] by Desmond King-Hele, 2002, The Royal Society, London. Accessed April 2008.</ref>
*'''[[Acoustic droplet ejection]]'''– (ADE) uses a pulse of ultrasound to move low volumes of fluids (typically nanoliters or picoliters) without any physical contact.  This technology focuses acoustic energy into a fluid sample in order to eject droplets as small as a [[Litre|picoliter]].  ADE technology is a very gentle process. This feature makes the technology suitable for a wide variety of applications including [[proteomics]] and cell-based assays.
*'''[[Active cooling]]''' – an ''active cooling'' system is one that involves the use of energy to cool something, as opposed to [[passive cooling]] that uses no energy.  Such systems circulate a [[coolant]] to [[Heat transfer|transfer heat]] from one place to another. The coolant is either a gas, such as in [[air cooling]] of [[Computer cooling|computers]], or a liquid such as in a  [[Radiator (engine cooling)|car engine]]. In the latter case, liquid is pumped to transfer heat from the engine to the radiator, which in turn is cooled by passing air over it.  Other active cooling systems make use of a [[Heat pump and refrigeration cycle|refrigeration cycle]]. 
*'''[[Actual mechanical advantage]]''' – The ''actual mechanical advantage'' (AMA) is the mechanical advantage determined by physical measurement of the input and output forces. AMA takes into account energy loss due to deflection, friction, and wear.
*'''[[Adjoint equation]]''' – is a [[linear differential equation]], usually derived from its primal equation using [[integration by parts]].  Gradient values with respect to a particular quantity of interest can be efficiently calculated by solving the adjoint equation. Methods based on solution of adjoint equations are used in [[wing shape optimization]], fluid flow control and [[uncertainty quantification]]. For example <math> dX_t = a(X_t)dt + b(X_t)dW</math> this is an [[Itō calculus|Itō]] stochastic differential equation. Now by using Euler scheme, we integrate the parts of this equation and get another equation, <math> X_{n+1} = X_n  +  a \Delta t + \zeta b \sqrt{\Delta t}</math>, here <math>\zeta</math> is a random variable, later one is an adjoint equation.
*'''[[Aerodynamics]]''' – the study of the motion of [[air]], particularly its interaction with a solid object, such as an [[airplane]] wing. It is a sub-field of [[fluid dynamics]] and [[gas dynamics]], and many aspects of aerodynamics theory are common to these fields.
*'''[[Agitator (device)]]''' – a [[machine|device]] or [[Mechanism (engineering)|mechanism]] to put something into [[Motion (physics)|motion]] by [[wikt:shaking|shaking]] or [[wikt:stirring|stirring]]. Agitators usually consist of an [[impeller]] and a shaft; an impeller is a rotor located within a tube or conduit attached to the shaft, which helps enhance the pressure in order for the flow of a fluid be done.<ref>{{Cite web|url=https://dein-hochdruckreiniger.de/|title=Pressure Washer|access-date=2017-02-23|archive-date=2017-02-24|archive-url=https://web.archive.org/web/20170224132339/https://dein-hochdruckreiniger.de/|url-status=dead}}</ref> 
*'''[[Air handler]]''' – an ''air handler'', or ''air handling unit'' (often abbreviated to ''AHU''), is a device used to regulate and circulate air as part of a heating, ventilating, and air-conditioning ([[HVAC]]) system.<ref name=ASHRAE>{{cite book|title=2008 ASHRAE handbook : heating, ventilating, and air-conditioning systems and equipment|year=2008|publisher=ASHRAE American Society of Heating, Refrigerating and Air-Conditioning Engineers|location=Atlanta, Ga.|isbn=9781933742335|edition=Inch-Pound}}</ref>
*'''[[Air compressor]]''' – a device that [[energy conversion|converts power]] (using an electric motor, diesel or gasoline engine, etc.) into [[potential energy]] stored in pressurized air (i.e., [[compressed air]]). By one of several methods, an air compressor forces more and more air into a storage tank, increasing the pressure. When tank pressure reaches its engineered upper limit the air compressor shuts off. The compressed air, then, is held in the tank until called into use.<ref>{{Cite news|url=http://www.popularmechanics.com/home/how-to/a151/how-air-compressors-work/|title=How Do Air Compressors Work?|date=2015-03-18|newspaper=Popular Mechanics|access-date=2017-01-12}}</ref> 
*'''[[Air conditioner]]''' – ''Air conditioning'' (often referred to as ''AC'', ''A/C'', or ''air con'')<ref>{{cite web|url= https://dictionary.cambridge.org/us/dictionary/english/air-con|title=air con Definition in the Cambridge English Dictionary |website=dictionary.cambridge.org |access-date=1 March 2018}}</ref> is the process of removing heat and moisture from the interior of an occupied space, to improve the comfort of occupants.  Air conditioning can be used in both domestic and commercial environments.
*'''[[Air preheater]]''' – (APH) any device designed to heat [[air]] before another process (for example,  [[combustion]] in a [[boiler]]) with the primary objective of increasing the thermal efficiency of the process. They may be used alone or to replace a [[recuperator|recuperative]] heat system or to replace a steam coil.
*'''[[Airflow]]''' – ''Airflow'', or ''air flow'', is the movement of air from one area to another. The primary cause of airflow is the existence of [[pressure gradient]]s. Air behaves in a [[fluid]] manner, meaning particles naturally flow from areas of higher pressure to those where the pressure is lower. [[Atmospheric pressure|Atmospheric air pressure]] is directly related to altitude, temperature, and composition.<ref>{{Cite news|url=https://www.thoughtco.com/winds-and-the-pressure-gradient-force-1434440|title=How Do Air Pressure Differences Cause Winds?|work=ThoughtCo|access-date=2017-11-09}}</ref><ref name=":2">ASHRAE, ed. ''ASHRAE Handbook of Fundamentals 2017''. Atlanta, GA: American Society of Heating, Air-Conditioning and Refrigeration Engineers, 2017.</ref>  In [[engineering]], airflow is a measurement of the amount of [[air]] per unit of time that flows through a particular device.
*'''[[Allowance (engineering)|Allowance]]''' – a planned deviation between an exact dimension and a [[Real versus nominal value|nominal]] or [[theoretical]] dimension, or between an intermediate-stage dimension and an intended final dimension. The unifying abstract concept is that a certain amount of difference ''allows for'' some known factor of compensation or interference. For example, an area of excess metal may be left because it is needed to complete subsequent machining. Common cases are listed below. An ''allowance,'' which is a ''planned'' deviation from an ideal, is contrasted with a ''[[Engineering tolerance|tolerance]],'' which accounts for expected but unplanned deviations.
*'''[[American Society of Mechanical Engineers]]''' – The ''American Society of Mechanical Engineers'' (''ASME'') is a [[professional association]] that, in its own words, "promotes the art, science, and practice of multidisciplinary engineering and allied sciences around the globe" via "[[continuing education]], training and [[professional development]], codes and [[technical standard|standards]], [[research]], conferences and publications, government relations, and other forms of outreach."<ref name="ASME_dot_org_slash_about-asme">{{Cite web |author=ASME|title=ASME.org > About ASME |url=http://www.asme.org/about-asme |access-date=2011-12-27 }}</ref> 
*'''[[Ampere]]''' – the [[SI base unit|base unit]] of [[electric current]] in the  [[International System of Units]] (SI).<ref name="BIPMdefinition">{{Citation|chapter= 2.1. Unit of electric current (ampere)|chapter-url= http://www.bipm.org/en/si/si_brochure/chapter2/2-1/ampere.html|title= SI brochure|edition= 8th|publisher= BIPM|access-date= 19 November 2011|url-status= live|archive-url= https://web.archive.org/web/20120203153904/http://www.bipm.org/en/si/si_brochure/chapter2/2-1/ampere.html|archive-date= 3 February 2012|df= dmy-all}}</ref><ref>[http://physics.nist.gov/cuu/Units/ampere.html Base unit definitions: Ampere] {{webarchive|url=https://web.archive.org/web/20170425134625/http://www.physics.nist.gov/cuu/Units/ampere.html |date=25 April 2017 }} Physics.nist.gov. Retrieved on 2010-09-28.</ref> It is named after [[André-Marie Ampère]] (1775–1836), French mathematician and physicist, considered the father of [[electrodynamics]].
*'''[[Applied mechanics]]''' – describes the behavior of a body, in either a beginning state of rest or of motion, subjected to the action of forces.<ref>''Engineering Mechanics (statics and dynamics)'' - Dr.N.Kottiswaran {{ISBN|978-81-908993-3-8}}</ref> Applied mechanics, bridges the gap between physical theory and its application to [[technology]].  It is used in many fields of [[engineering]], especially [[mechanical engineering]] and [[civil engineering]]. In this context, it is commonly referred to as ''engineering mechanics''.
*'''[[Archimedes' screw]]''' – also known by the name ''Archimedean screw'' or ''screw pump'', is a [[machine]] used for [[pump|transferring water]] from a low-lying body of water into [[irrigation]] ditches. Water is pumped by turning a screw-shaped surface inside a pipe.  The [[screw pump]] is commonly attributed to [[Archimedes]],<ref name="Oleson 2000 242–251">{{harvnb|Oleson|2000|pp=242–251}}</ref> 
*'''[[Artificial intelligence]]''' – ('''AI'''), sometimes called ''[[machine]] intelligence'', is [[intelligence]] demonstrated by [[machine]]s, in contrast to the ''[[natural]] intelligence''<!--boldface per WP:R#PLA--> displayed by humans and other animals.  In [[computer science]]  AI research is defined as the study of "[[intelligent agent]]s": any device that perceives its environment and takes actions that maximize its chance of successfully achieving its goals.<ref name="Definition of AI">
Definition of AI as the study of [[intelligent agents]]:
* {{Harvnb|Poole|Mackworth|Goebel|1998|loc=[http://people.cs.ubc.ca/~poole/ci/ch1.pdf p. 1]}}, which provides the version that is used in this article. Note that they use the term "computational intelligence" as a synonym for artificial intelligence.
* {{Harvtxt|Russell|Norvig|2003}} (who prefer the term "rational agent") and write "The whole-agent view is now widely accepted in the field" {{Harv|Russell|Norvig|2003|p=55}}.
* {{Harvnb|Nilsson|1998}}
<!--These textbooks are the most widely used in academic AI.-->
* {{Harvnb|Legg|Hutter|2007}}.
</ref> Colloquially, the term "artificial intelligence" is applied when a machine mimics "cognitive" functions that humans associate with other [[human mind]]s, such as "learning" and "problem solving".{{sfn|Russell|Norvig|2009|p=2}} 
*'''[[Technical drawing#sets of technical drawings|Assembly drawing]]''' – ''see'' Technical drawing.
*'''[[Automaton clock]]''' – An ''automaton clock'' or ''automata clock'' is a type of [[striking clock]] featuring [[automaton]]s.<ref>{{Cite web
| url = http://www.vam.ac.uk/content/videos/m/musical-automaton-clock/
| title = Musical automaton clock
| date = 13 January 2011
| access-date = 2011-09-16
| publisher = Victoria and Albert Museum, London
}}</ref> Clocks like these were built from the 1st century BC through to [[Victorian era|Victorian]] times in Europe. A [[cuckoo clock]] is a simple form of this type of clock.
*'''[[Automobile]]''' – a wheeled [[motor vehicle]] used for [[transportation]].  Most definitions of ''car'' say they run primarily on roads, seat one to eight people, have four [[tyre (wheel)|tires]], and mainly transport people rather than goods.<ref>{{cite book |title=Pocket Oxford Dictionary |url=https://archive.org/details/australianpocket00john |url-access=registration |year=1976 |publisher=Oxford University Press  |isbn=978-0198611134 |editor-last=Fowler |editor-first=H.W. |editor-last2=Fowler |editor-first2=F.G.}}</ref><ref name="OEDmotrcar">{{cite web | url=http://www.oed.com/view/Entry/122742#eid35698343 | title=motor car, n. | publisher=Oxford University Press | work=OED Online | date=September 2014 | access-date=2014-09-29}}</ref>
*'''[[Automobile handling]]''' – ''Automobile handling'' and ''vehicle handling'' are descriptions of the way a wheeled vehicle responds and reacts to the inputs of a driver, as well as how it moves along a track or road. It is commonly judged by how a vehicle performs particularly during [[Cornering force|cornering]], acceleration, and braking as well as on the vehicle's [[directional stability]] when moving in steady state condition. 
*'''[[Automotive engineering]]''' – ''Automotive engineering'', along with [[aerospace engineering]] and [[Naval architecture|marine engineering]], is a branch of vehicle engineering, incorporating elements of [[Mechanical engineering|mechanical]], [[Electrical engineering|electrical]], [[Electronic engineering|electronic]], [[Software engineering|software]] and [[safety engineering]] as applied to the design, manufacture and operation of [[motorcycles]], [[automobile]]s and [[truck]]s and their respective engineering subsystems. It also includes modification of vehicles. Manufacturing domain deals with the creation and assembling the whole parts of automobiles is also included in it. The automotive engineering field is research -intensive and involves direct application of mathematical models and formulas. The study of automotive engineering is to design, develop, fabricate, and testing vehicles or vehicle components from the concept stage to production stage. Production, development, and manufacturing are the three major functions in this field.
*'''[[Axle]]''' – a central shaft for a [[rotation|rotating]] wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to the vehicle, with the wheels rotating around the axle.<ref>{{cite book|title=Mechanical Engineering design|date=2010|publisher=McGraw Hill|isbn=978-0073529288|pages=360|edition=9th|url=https://www.bookdepository.com/Shigleys-Mechanical-Engineering-Design-Richard-G-Budynas/9780073529288}}</ref>  In the former case, [[bearing (mechanical)|bearings]] or [[Bushing (bearing)|bushings]] are provided at the mounting points where the axle is supported.  In the latter case, a bearing or bushing sits inside a central hole in the wheel to allow the wheel or gear to rotate around the axle.  Sometimes, especially on bicycles, the latter type axle is referred to as a ''[[spindle (tool)|spindle]]''.

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==B==
*'''[[Babbitt (alloy)|Babbitt]]''' – also called ''Babbitt metal'' or ''bearing metal'', is any of several [[alloy]]s used for the [[bearing surface]] in a [[plain bearing]]. The original Babbitt alloy was invented in 1839 by [[Isaac Babbitt]]<ref>{{The Timetables of Science|pages=305}}</ref> in [[Taunton, Massachusetts|Taunton]], [[Massachusetts]], United States.
*'''[[Backdrive]]''' – a component used in reverse to obtain its input from its output. This extends to many concepts and systems from thought based to practical mechanical applications.
*'''[[Backlash (gear)|Backlash]]''' – sometimes called ''lash'' or ''play'', is a clearance or lost motion in a mechanism caused by gaps between the parts. It can be defined as "the maximum distance or angle through which any part of a [[mechanical system]] may be moved in one direction without applying appreciable force or motion to the next part in mechanical sequence",<ref name=bag09>{{cite book|last1=Bagad|first1=V.S.|title=Mechatronics|date=2009|publisher=Technical Publications|location=Pune|isbn=9788184314908|edition=4th revised|url=https://books.google.com/books?id=NCEeONKWzX4C&dq=backlash&pg=SA1-PA8|access-date=28 June 2014}}{{Dead link|date=June 2024 |bot=InternetArchiveBot |fix-attempted=yes }}</ref><sup>p.&nbsp;1-8<!--section 1 page 8--></sup>.
*'''[[Balancing machine]]''' – a measuring tool used for balancing rotating machine parts such as rotors for [[electric motor]]s, fans, [[turbine]]s, [[disc brake]]s, [[disk storage|disc drives]], [[propeller]]s and [[pump]]s. 
*'''[[Ball detent]]''' – a simple mechanical arrangement used to hold a moving part in a temporarily fixed position relative to another part. Usually the moving parts slide with respect to each other, or one part rotates within the other.
*'''[[Ball screw]]''' – a mechanical [[linear actuator]] that translates rotational motion to linear motion with little [[friction]].  A threaded shaft provides a helical raceway for [[ball bearing]]s which act as a precision screw. As well as being able to apply or withstand high thrust loads, they can do so with minimum internal friction. 
*'''[[Ball spline]]''' – ''Ball splines'' (Ball Spline [[Bearing (mechanical)|bearing]]s) are a special type of [[linear motion bearing]] that are used to provide nearly frictionless linear motion while allowing the member to transmit torque simultaneously. There are [[Groove (engineering)|grooves]] ground along the length of the shaft (thus forming [[Rotating spline|splines]]) for the recirculating ground balls to run inside. The outer shell that houses the balls is called a nut rather than a [[Bushing (bearing)|bushing]], but is not a nut in the traditional sense—it is not free to rotate about the shaft, but is free to travel up and down the shaft. 
*'''[[Beale number]]''' – a parameter that characterizes the performance of [[Stirling engine]]s.  It is often used to estimate the power output of a Stirling engine design.  For engines operating with a high temperature differential, typical values for the Beale number range from ( 0.11 ) to ( 0.15 ); where a larger number indicates higher performance.
*'''[[Bearing (mechanical)|Bearing]]''' – a [[machine element]] that constrains relative motion to only the desired motion, and reduces [[friction]] between [[moving parts]].
*'''[[Bearing pressure]]''' – a particular case of [[contact mechanics]] often occurring in cases where a convex surface (male cylinder or sphere) contacts a concave surface (female cylinder or sphere: [[Boring (manufacturing)|bore]] or [[Spherical bearing|hemispherical cup]]). Excessive contact pressure can lead to a typical bearing failure such as a plastic deformation similar to [[peening]]. This problem is also referred to as ''bearing resistance''.<ref name="Eurocode3">EN 1993-1-8:2005 ''[[Eurocode 3]]: Design of steel structures - Part 1-8: Design of joints''</ref>
*'''[[Bearing surface]]''' – the [[area]] of contact between two objects. It usually is used in reference to [[bolted joint]]s and [[bearing (mechanical)|bearings]], but can be applied to a wide variety of engineering applications. On a [[screw]] the bearing area loosely refers to the underside of the head.<ref>{{harvnb|Smith|1990|p=38}}.</ref> Strictly speaking, the bearing area refers to the area of the screw head that directly bears on the part being fastened.<ref>{{Citation | title = Fastener terms | url = http://www.canadianstainless.ca/page9.html | access-date = 2009-06-29 | archive-url = https://web.archive.org/web/20081102235557/http://www.canadianstainless.ca/page9.html | archive-date = 2008-11-02 | url-status = dead }}.</ref> For a cylindrical bearing it is the [[projected area]] perpendicular to the applied force.<ref>{{harvnb|Low|Bevis|1908|p=115}}.</ref>  On a [[spring (device)|spring]] the bearing area refers to the amount of area on the top or bottom surface of the spring in contact with the constraining part.<ref>{{Citation | title = Helical Compression Spring Terminology | url = http://www.masterspring.com/technical_resources/helical_compression_spring_terminology/default.html | access-date = 2009-06-29 | archive-url = https://web.archive.org/web/20101101174850/http://www.masterspring.com/technical_resources/helical_compression_spring_terminology/default.html | archive-date = 2010-11-01 | url-status = dead }}.</ref> The ways of [[machine tool]]s, such as dovetail slides, box ways, prismatic ways, and other types of machine slides are also bearing surfaces. 
*'''[[Belt (mechanical)|Belt]]''' – a loop of flexible material used to link two or more rotating [[Drive shaft|shafts]] mechanically, most often parallel. Belts may be used as a source of motion, to [[Transmission (mechanics)|transmit power]] efficiently or to track relative movement. Belts are looped over [[pulley]]s and may have a twist between the pulleys, and the shafts need not be parallel.
*'''[[Belt friction]]''' – describes the friction forces between a [[Belt (mechanical)|belt]] and a surface, such as a belt wrapped around a [[bollard]]. When one end of the belt is being pulled only part of this force is transmitted to the other end wrapped about a surface. The friction force increases with the amount of wrap about a surface and makes it so the [[tension (physics)|tension]] in the belt can be different at both ends of the belt. Belt friction can be modeled by the [[Capstan equation|Belt friction equation]].<ref name=Attaway>{{cite conference | last = Attaway | first = Stephen W. | title = The Mechanics of Friction in Rope Rescue | url = http://www.jrre.org/att_frict.pdf | access-date = February 1, 2010 | conference = International Technical Rescue Symposium | year = 1999}}</ref>
*'''[[Bending]]''' – In [[applied mechanics]], ''bending'' (also known as ''flexure'') characterizes the behavior of a slender [[structural]] element subjected to an external [[Structural load|load]] applied perpendicularly to a longitudinal axis of the element.
*'''[[Biomechatronics]]''' – an applied [[interdisciplinary]] science that aims to integrate [[biology]], [[mechanics]], and [[electronics]]. It also encompasses the fields of [[robotics]] and [[neuroscience]]. Biomechatronic devices encompass a wide range of applications from the development of [[Prosthesis|prosthetic limbs]] to engineering solutions concerning respiration, vision, and the cardiovascular system.<ref>{{Cite book|title=Introduction to Biomechatronics|last=Brooker|first=Graham|publisher=University of Sydney, Australia|year=2012|isbn=978-1-891121-27-2}}</ref>
*'''[[Body in white]]''' – or ''BIW'' refers to the stage in [[Automotive industry|automobile manufacturing]] in which a car body's components have been joined together, using one or a combination of different techniques: welding (spot, MIG/MAG), riveting, clinching, bonding, laser brazing etc. BIW is termed before painting and before the engine, chassis sub-assemblies, or trim (glass, door locks/handles, seats, upholstery, electronics, etc.) have been assembled in the frame structure.
*'''[[Bogie]]''' – a [[chassis]] or framework that carries a [[Wheelset (rail transport)|wheelset]], attached to a vehicle—a [[Modularity|modular]] subassembly of [[Railroad wheel|wheels]] and [[axle]]s. Bogies take various forms in various modes of transport.
*'''[[Bonded seal]]''' – a type of [[Washer (hardware)|washer]] used to provide a [[mechanical seal|seal]] around a screw or bolt. Originally made by [[Dowty Group]], they are also known as Dowty seals or Dowty washers.<ref>{{cite web|url=http://www.potterassoc.com/pdf/bonded_seal_information_and_sizing_chart.pdf|title=The Dowty Bonded Seal|access-date=12 August 2016|archive-date=22 February 2016|archive-url=https://web.archive.org/web/20160222000527/http://www.potterassoc.com/pdf/bonded_seal_information_and_sizing_chart.pdf|url-status=dead}}</ref> Now widely manufactured, they are available in a range of standard sizes and materials <ref>{{cite web|url=http://www.ashtonseals.com/bonded-seals.asp|title=Bonded Seals from Ashton Seals|access-date=12 August 2016}}</ref><ref>{{cite web|url=http://www.easternseals.co.uk/products/bonded-seals/|title=Bonded Seals from Eastern Seals|access-date=12 August 2016}}</ref><ref>{{cite web|url=http://supaseal.co.uk/datasheets/bonded_seals.pdf|title=Bonded Seals from Supaseal|access-date=12 August 2016}}</ref>
*'''[[Brittleness]]''' – A material is ''brittle'' if, when subjected to [[stress (physics)|stress]], it breaks without significant [[Plastic Deformation|plastic deformation]]. Brittle materials absorb relatively little [[energy]] prior to fracture, even those of high [[Strength of materials|strength]].
*'''[[Buckling]]''' – instability that leads to a [[structural failure|failure mode]]. When a structure is subjected to [[Compression (physics)|compressive]] [[Stress (mechanics)|stress]], buckling may occur. Buckling is characterized by a sudden sideways deflection of a structural member. This may occur even though the stresses that develop in the structure are well below those needed to cause failure of the material of which the structure is composed.
*'''[[Bus]]''' – A ''bus'' (archaically also ''omnibus'',<ref name=EB1911>{{cite EB1911 |wstitle=Omnibus |volume=20 |page=104}}</ref> ''multibus'', ''motorbus'', and ''autobus'') is a [[road vehicle]] designed to carry many [[passenger]]s.
*'''[[Bushing (isolator)|Bushing]]''' – or ''rubber bushing'' is a type of [[Vibration isolation|vibration isolator]]. It provides an interface between two parts, damping the energy transmitted through the bushing. A common application is in [[Suspension (vehicle)|vehicle suspension]] systems, where a bushing made of [[rubber]] (or, more often, [[synthetic rubber]] or [[polyurethane]]) separates the faces of two metal objects while allowing a certain amount of movement. This movement allows the suspension parts to move freely, for example, when traveling over a large bump, while minimizing transmission of noise and small vibrations through to the chassis of the vehicle. A rubber bushing may also be described as a ''flexible mounting'' or ''antivibration mounting''.
*'''[[Boiler]]''' – a closed [[pressure vessel|vessel]] in which [[fluid]] (generally water) is heated. The fluid does not necessarily [[boiling|boil]]. The heated or vaporized fluid exits the boiler for use in various processes or heating applications,<ref>{{cite book|author=Frederick M. Steingress|title=Low Pressure Boilers |edition=4th |publisher=American Technical Publishers|year=2001|isbn=0-8269-4417-5}}</ref><ref>{{cite book|author=Frederick M. Steingress, Harold J. Frost and Darryl R. Walker|title=High Pressure Boilers|edition=3rd |publisher=American Technical Publishers|year=2003|isbn=0-8269-4300-4}}</ref> including [[Boiler (water heating)|water heating]], [[central heating]], [[boiler (power generation)|boiler-based power generation]], [[cooking]], and [[sanitation]].

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==C==
*'''[[Computer-aided design|CAD]]''' – ''see'' Computer-aided design.
*'''[[Computer-aided manufacturing|CAM]]''' – ''see'' Computer-aided manufacturing
*'''[[Computer-aided industrial design|CAID]]''' – ''see'' Computer-aided industrial design.
*'''[[Calculator]]''' – An ''electronic calculator'' is typically a portable [[Electronics|electronic]] device used to perform [[calculation]]s, ranging from basic [[arithmetic]] to complex [[mathematics]].
*'''[[Calculus]]''' – the [[mathematics|mathematical]] study of <!-- Please, do not link "continuous", it has the common-language meaning, and does not refer to the technical mathematical concept -->continuous change.
*'''[[Automobile handling|Car handling]]''' – ''Automobile handling'' and ''vehicle handling'' are descriptions of the way a wheeled vehicle responds and reacts to the inputs of a driver, as well as how it moves along a track or road. It is commonly judged by how a vehicle performs particularly during [[Cornering force|cornering]], acceleration, and braking as well as on the vehicle's [[directional stability]] when moving in steady state condition.
*'''[[Carbon fiber reinforced polymer]]''' – or ''carbon fiber reinforced plastic'', or ''carbon fiber reinforced thermoplastic'' (''CFRP'', ''CRP'', ''CFRTP'', or often simply ''carbon fiber'', ''carbon composite'', or even ''carbon''), is an extremely strong and light [[fiber-reinforced plastic]] which contains [[carbon fibers]].
*'''[[Carbon fibers]]''' – or ''carbon fibres'' (alternatively ''CF'', ''graphite fiber'' or ''graphite fibre'') are [[fiber]]s about 5–10 [[micrometre]]s in diameter and composed mostly of [[carbon]] atoms. Carbon fibers have several advantages including high stiffness, high tensile strength, low weight, high chemical resistance, high temperature tolerance and low thermal expansion. These properties have made carbon fiber very popular in aerospace, civil engineering, military, and motorsports, along with other competition sports. However, they are relatively expensive when compared with similar fibers, such as [[glass fiber]]s or plastic fibers.
*'''[[Classical mechanics]]''' – describes the [[motion (physics)|motion]] of [[macroscopic]] objects, from [[projectile]]s to parts of [[Machine (mechanical)|machinery]], and [[astronomical objects]], such as [[spacecraft]], [[planets]], [[star]]s and [[galaxies]].
*'''[[Clean room design]]''' – the method of copying a design by [[reverse engineering]] and then recreating it without infringing any of the [[copyright]]s associated with the original design. Clean-room design is useful as a defense against copyright infringement because it relies on independent invention. However, because independent invention is not a defense against [[patent]]s, clean-room designs typically cannot be used to circumvent patent restrictions.
*'''[[Clevis fastener]]''' – a fastener consisting of a U-shaped bracket through which a pin is placed
*'''[[Clock]]''' – an instrument used to measure, keep,<!-- Per [[WP:RETAIN]] and [[MOS:OXFORD]], please do not remove comma without consensus on the talk page --> and indicate [[time]]. The clock is one of the oldest human [[invention]]s, meeting the need to measure intervals of time shorter than the natural units: the day, the [[lunar month]],<!-- Per WP:RETAIN and MOS:OXFORD, please do not remove comma without consensus on the talk page --> and the year. Devices operating on several physical processes have been used over the millennia.
*'''[[Clutch]]''' – a mechanical device which engages and disengages power transmission especially from [[drive shaft|driving shaft]] to driven shaft.
*'''[[Numerical control|CNC]]''' – ('''CNC''')), the [[automation|automated control]] of [[machining]] tools (drills, boring tools, lathes) by means of a [[computer]]. An NC machine alters a blank piece of material (metal, plastic, wood, ceramic, or composite) to meet precise specifications by following programmed instructions and without a manual operator.
*'''[[Coefficient of thermal expansion]]''' – describes how the size of an object changes with a change in temperature. Specifically, it measures the fractional change in size per degree change in temperature at a constant pressure. Several types of coefficients have been developed: volumetric, area, and linear. The choice of coefficient depends on the particular application and which dimensions are considered important.
*'''[[Coil spring]]''' – also known as a ''helical spring'', is a mechanical device which is typically used to store energy and subsequently release it, to absorb shock, or to maintain a force between contacting surfaces.  They are made of an [[Elasticity (physics)|elastic]] material formed into the shape of a [[helix]] which returns to its natural length when unloaded.
*'''[[Combustion]]''' – also known as ''burning'' when accompanied by fire, is a high-temperature [[exothermic]] [[redox]] [[chemical reaction]] between a [[fuel]] (the reductant) and an [[oxidant]], usually atmospheric [[oxygen]], that produces oxidized, often gaseous products, in a mixture as [[smoke]]. Generally, the [[chemical equation]] for [[Stoichiometry|stoichiometric]] combustion of a [[hydrocarbon]] in oxygen is <chem>C_\mathit{x}H_\mathit{y}{} + \mathit{z}O2 -> \mathit{x}CO2{} + \frac{\mathit{y}}{2}H2O</chem>, where <math>z = x + \frac{y}{4}</math>. 
*'''[[Composite material]]''' – (also called a ''composition material'', or shortened to ''composite''), is a material made from two or more constituent materials with significantly different [[Physical property|physical]] or [[Chemical property|chemical properties]] that, when combined, produce a material with characteristics different from the individual components. The individual components remain separate and distinct within the finished structure, differentiating composites from [[mixture]]s and [[solid solution]]s.
*'''[[Compression ratio]]''' – The static ''compression ratio'', (symbol <math>\varepsilon</math>),<ref>{{Cite book|title=Kfz-Rechnen|last1=Lutjen|first1=D|last2=Müller|first2=M|date=1984|publisher=B.G. Teubner Stuttgart|isbn=9783519067214|pages=12}}</ref> of an [[internal combustion engine]] or [[external combustion engine]] is a value that represents the [[ratio]] of the volume of its [[combustion chamber]] from its largest capacity to its smallest capacity. It is a fundamental specification for many common combustion engines.
*'''[[Compressive strength]]''' – or ''compression strength'', is the capacity of a material or structure to withstand loads tending to reduce size, as opposed to [[Ultimate tensile strength|tensile strength]], which withstands loads tending to elongate. In other words, compressive strength resists [[Compression (physics)|compression]] (being pushed together), whereas tensile strength resists [[Tension (physics)|tension]] (being pulled apart). In the study of [[strength of materials]], tensile strength, compressive strength, and [[shear strength]] can be analyzed independently.
*'''[[Computational fluid dynamics]]''' – ('''CFD''') a branch of [[fluid mechanics]] that uses [[numerical analysis]] and [[data structure]]s to analyze and solve problems that involve [[fluid dynamics|fluid flows]].  Computers are used to perform the calculations required to simulate the free-stream flow of the fluid, and the interaction of the fluid ([[liquid]]s and [[gas]]es) with surfaces defined by [[Boundary value problem#Boundary value conditions|boundary conditions]]. With high-speed [[supercomputer]]s, better solutions can be achieved, and are often required to solve the largest and most complex problems. 
*'''[[Computer]]''' – a device that can be instructed to carry out [[sequence]]s of [[arithmetic]] or [[Boolean algebra|logical]] operations automatically via [[computer programming]]. Modern computers have the ability to follow generalized sets of operations, called ''[[Computer program|programs]].'' These programs enable computers to perform an extremely wide range of tasks. A "complete" computer including the [[Computer hardware|hardware]], the [[operating system]] (main [[software]]), and [[peripheral]] equipment required and used for "full" operation can be referred to as a '''computer system'''. This term may as well be used for a group of computers that are connected and work together, in particular a [[computer network]] or [[computer cluster]].
*'''[[Computer-aided design]]''' – ('''CAD''') the use of [[computer system]]s (or {{vanchor|[[workstation]]s|WORKSTATION}}) to aid in the creation, modification, analysis, or optimization of a [[design]].<ref>{{cite book|last=Narayan|first=K. Lalit|title=Computer Aided Design and Manufacturing|year=2008|publisher=Prentice Hall of India|location=New Delhi|page=3|url=https://books.google.com/books?id=zXdivq93WIUC|isbn=978-8120333420}}</ref> CAD software is used to increase the productivity of the designer, improve the quality of design, improve communications through documentation, and to create a database for manufacturing.<ref>{{cite book|last=Narayan|first=K. Lalit|title=Computer Aided Design and Manufacturing|year=2008|publisher=Prentice Hall of India|location=New Delhi|page=4|url=https://books.google.com/books?id=zXdivq93WIUC|isbn=978-8120333420}}</ref> CAD output is often in the form of electronic files for print, machining, or other manufacturing operations. The term '''CADD''' (for ''Computer Aided Design and Drafting'') is also used.<ref>{{cite book|last=Duggal |first=Vijay |year=2000 |title=Cadd Primer: A General Guide to Computer Aided Design and Drafting-Cadd, CAD |isbn=978-0962916595 |publisher=Mailmax Pub}}</ref>
*'''[[Computer-aided industrial design]]''' – ('''CAID''') a subset of [[computer-aided design]] (CAD) software that can assist in creating the look-and-feel, or industrial design aspects of a product in development.
*'''[[Computer-aided manufacturing]]''' – ('''CAM''') the use of software to control [[machine tool]]s and related ones in the [[manufacturing]] of workpieces.<ref name="ota">{{cite book | last = [[U.S. Congress]], [[Office of Technology Assessment]] | title = Computerized manufacturing automation | page = 48 | publisher= DIANE Publishing | year = 1984 | url = https://books.google.com/books?id=LYdF5akRL6sC&pg=PA48 | isbn = 978-1-4289-2364-5}}</ref><ref>{{Citation | last1 = Hosking | first1 = Dian Marie | last2 = Anderson | first2 = Neil | title = Organizational change and innovation | page = 240 | publisher = Taylor & Francis | year = 1992 | url = https://books.google.com/books?id=TbwOAAAAQAAJ&pg=PA240 | isbn = 978-0-415-06314-2}}</ref><ref name="daintith">{{cite book | last = Daintith | first = John | title = A dictionary of computing | page = 102 | publisher = Oxford University Press | year = 2004 | edition = 5 | url = https://books.google.com/books?id=Hay6vTsGFAsC&pg=PA102 | isbn = 978-0-19-860877-6}}</ref><ref>{{cite book| last = Kreith | first = Frank | author-link= Frank Kreith | title = The CRC handbook of mechanical engineering | page = 15-1<!-- Not a range. --> | publisher = CRC Press | year = 1998| url = https://books.google.com/books?id=OpD226SXKisC&pg=PT1972 | isbn = 978-0-8493-9418-8 }}</ref><ref>{{cite book | last = Matthews | first = Clifford | title = Aeronautical engineer's data book | page = 229 | publisher = Butterworth-Heinemann | year = 2005 | edition = 2nd | url = https://books.google.com/books?id=5W9Rqq3qP1QC| isbn = 978-0-7506-5125-7}}</ref> This is not the only definition for CAM, but it is the most common;<ref name="ota"/> CAM may also refer to the use of a computer to assist in all operations of a manufacturing plant, including planning, management, transportation and storage.<ref>{{cite book| last1 = Pichler | first1 = Franz | last2 = Moreno-Díaz | first2 = Roberto | title = Computer aided systems theory | page = 602 | publisher = Springer | year = 1992 | url = https://books.google.com/books?id=xmHL8KONTXUC&pg=PA602 | isbn = 978-3-540-55354-0}}</ref><ref>{{cite book | last1 = Boothroyd | first1 = Geoffrey | last2 = Knight | first2 = Winston Anthony | title = Fundamentals of machining and machine tools | page = 401 | publisher = CRC Press | year = 2006 | edition = 3rd | url = https://books.google.com/books?id=Y0cRCFalmekC&pg=PA401 | isbn = 978-1-57444-659-3}}</ref>
*'''[[Numerical control|Computer numerical control]]''' – ''Numerical control'' (''NC''), (also ''computer numerical control'' (''CNC'')), is the [[automation|automated control]] of [[machining]] tools (drills, boring tools, lathes) and [[3D printer]]s by means of a [[computer]]. An NC machine alters a blank piece of material (metal, plastic, wood, ceramic, or composite) to meet precise specifications by following programmed instructions and without a manual operator. 
*'''[[Conservation of mass]]''' – The ''law of conservation of mass'' or ''principle of mass conservation'' states that for any [[closed system|system closed]] to all transfers of [[matter]] and [[energy]], the [[mass]] of the system must remain constant over time, as system's mass cannot change, so quantity can neither be added nor be removed. Hence, the quantity of mass is conserved over time.
*'''[[Constant-velocity joint]]''' – (also known as ''homokinetic'' or ''CV joints''), allow a [[drive shaft]] to transmit power through a variable angle, at constant rotational speed, without an appreciable increase in friction or [[Backlash (engineering)|play]]. They are mainly used in [[front wheel drive]] vehicles. Modern [[rear wheel drive]] [[automobile|car]]s with [[independent rear suspension]] typically use CV joints at the ends of the rear axle halfshafts and increasingly use them on the [[drive shaft]]s.
*'''[[Constraint algorithm (mechanics)|Constraint]]''' –
*'''[[Continuum mechanics]]''' – a branch of [[mechanics]] that deals with the mechanical behavior of materials modeled as a continuous mass rather than as discrete particles.
*'''[[Control theory]]''' – in [[Control engineering|control systems engineering]] is a subfield of [[mathematics]] that deals with the control of continuously operating [[dynamical system]]s  in engineered processes and machines. The objective is to develop a control model for controlling such systems using a control action in an optimum manner without ''delay or overshoot'' and ensuring control [[Stability theory|stability]].
*'''[[Corrosion]]''' – a [[Erosion|natural process]] that converts a refined metal to a more chemically-stable form, such as its [[oxide]], [[hydroxide]], or [[sulfide]]. It is the gradual destruction of materials (usually [[metal]]s) by chemical and/or electrochemical reaction with their environment.  [[Corrosion engineering]] is the field dedicated to controlling and stopping corrosion.
*'''[[Split pin|Cotter pin]]''' – a pin or wedge passing through a hole to fix parts tightly together.
*'''[[Crankshaft]]''' – a mechanical part able to perform a conversion between [[reciprocating motion]] and [[rotational motion]]. In a [[reciprocating engine]], it translates [[reciprocating motion]] of the [[piston]] into rotational motion; whereas in a [[reciprocating compressor]], it converts the rotational motion into reciprocating motion. In order to do the conversion between two motions, the crankshaft has "crank throws" or "[[crankpin]]s", additional bearing surfaces whose axis is offset from that of the crank, to which the "big ends" of the [[connecting rod]]s from each cylinder attach.
*'''[[Cybernetics]]''' –

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==D==
*'''[[Damping ratio]]''' – an influence within or upon an [[oscillator|oscillatory system]] that has the effect of reducing, restricting or preventing its oscillations. In physical systems, damping is produced by processes that dissipate the energy stored in the oscillation.<ref>{{cite book
| title = An Introduction to Mechanical Vibrations
| author = Steidel
| year = 1971
| publisher = John Wiley & Sons
| page = 37
| quote = ''damped'', which is the term used in the study of vibration to denote a dissipation of energy}}</ref> Examples include [[Viscosity|viscous]] [[Drag (physics)|drag]] in mechanical systems, [[Electrical resistance and conductance|resistance]] in [[electronic oscillators]], and absorption and scattering of light in [[optical oscillator]]s.
*'''[[Deformation (engineering)]]''' – refers to the change in size or shape of an object. Deformation that is reversible is termed as [[Elasticity (physics) |elastic deformation]], while irreversible deformation is termed [[Plasticity (physics) |plastic deformation]]. ''Strain'' is the relative deformation of an infinitesimally small cube of material, and is generally linearly proportional to the forces or [[Stress (mechanics) |stresses]] acting on the cube while the deformation is elastic. The determination of the stress and strain throughout a solid object is given by the field of [[strength of materials]] and for a structure by [[structural analysis]].
*'''[[Delamination]]''' – is a mode of failure where a material [[fracture]]s into layers. A variety of materials including [[Lamination|laminate]] [[Composite material|composites]]<ref>{{Cite journal|last1=Cantwell|first1=W.J.|last2=Morton|first2=J.|date=1991|title=The impact resistance of composite materials — a review|journal=Composites|language=en|volume=22|issue=5|pages=347–362|doi=10.1016/0010-4361(91)90549-V}}</ref> and [[concrete]] can fail by delamination.
*'''[[Design]]''' –
*'''[[Design for manufacturability]]''' – (also sometimes known as design for manufacturing or DFM), is the general engineering practice of [[product design|designing]] products in such a way that they are easy to manufacture.  The concept exists in almost all engineering disciplines, but the implementation differs widely depending on the manufacturing technology.
*'''[[Diesel engine]]''' – (also known as a compression-ignition or CI engine), named after [[Rudolf Diesel]], is an [[internal combustion engine]] in which [[Combustion|ignition]] of the [[diesel fuel|fuel]] is caused by the elevated temperature of the air in the cylinder due to the mechanical compression ([[adiabatic compression]]).
*'''[[Differential (mechanics)|Differential]]''' –A differential is a gear train with three shafts that has the property that the rotational speed of one shaft is the average of the speeds of the others, or a fixed multiple of that average.
*'''[[Dimensionless number]]''' – a [[quantity]] to which no [[dimensional analysis|physical dimension]] is assigned. Dimensionless quantities are [[List of dimensionless quantities|widely used in many fields]], such as [[mathematics]], [[physics]], [[chemistry]], [[engineering]], and [[economics]].
*'''[[Diode]]''' – a two-[[Terminal (electronics)|terminal]] [[electronic component]] that conducts [[Electric current|current]] primarily in one direction (asymmetric [[electrical conductance|conductance]]); it has low (ideally zero) [[electrical resistance and conductance|resistance]] in one direction, and high (ideally infinite) [[Electrical resistance and conductance|resistance]] in the other. A diode [[vacuum tube]] or ''thermionic diode'' is a vacuum tube with two [[electrode]]s, a heated [[cathode]] and a [[plate electrode|plate]], in which electrons can flow in only one direction, from cathode to plate. A ''semiconductor diode'', the most commonly used type today, is a [[Crystallinity|crystalline]] piece of [[semiconductor]] material with a [[p–n junction]] connected to two electrical terminals.<ref>{{cite web|url=https://www.element14.com/community/docs/DOC-22519/l/physical-explanation-general-semiconductors |title=Physical Explanation – General Semiconductors |date=2010-05-25 |access-date=2010-08-06}}</ref>
*'''[[Diode laser]]''' –
*'''[[Docking sleeve]]''' –
*'''[[Technical drawing|Drafting]]''' –
*'''[[Drifting (motorsport)|Drifting]]''' –
*'''[[Driveshaft]]''' – a component for transmitting mechanical [[power (physics)|power]] and [[torque]] and rotation, usually used to connect other components of a [[drivetrain]] that cannot be connected directly because of distance or the need to allow for relative movement between them.
*'''[[Dynamics (mechanics)|Dynamics]]''' – the [[Branch (academia)#Physics|branch]] of [[classical mechanics]] that is concerned with the study of [[force (physics)|force]]s and their effects on [[Motion (physics)|motion]].
*'''[[Dynamometer]]''' – a device for simultaneously measuring the [[torque]] and [[rotational speed]] ([[Revolutions per minute|RPM]]) of an [[Heat engine|engine]], [[Electric motor|motor]] or other rotating [[Wiktionary:prime mover|prime mover]] so that its instantaneous [[Power (physics)|power]] may be calculated.

==E==
*'''[[Elasticity (physics)|Elasticity]]''' – In [[physics]], elasticity is the ability of a body to resist a distorting influence and to return to its original size and shape when that influence or force is removed.  Solid objects will [[Deformation (engineering)|deform]] when adequate [[Structural load|forces]] are applied to them.  If the material is elastic, the object will return to its initial shape and size when these forces are removed. Hooke's law states that the force should be proportional to the extension.  The physical reasons for elastic behavior can be quite different for different materials.  In metals, the atomic lattice changes size and shape when forces are applied (energy is added to the system).  When forces are removed, the lattice goes back to the original lower energy state.  For [[rubber elasticity|rubbers]] and other polymers, elasticity is caused by the stretching of polymer chains when forces are applied.
*'''[[Electric current]]''' – a stream of [[charged particles]], such as [[electrons]] or [[ions]], moving through an [[electrical conductor]] or space. It is measured as the net rate of flow of [[electric charge]] through a surface or into a [[control volume]].
*'''[[Electric motor]]''' – an [[electric machine|electrical machine]] that converts [[electrical energy]] into [[mechanical energy]]. Most electric motors operate through the interaction between the motor's [[magnetic field]] and [[electric current]] in a [[electromagnetic coil|wire winding]] to generate force in the form of [[rotation]] of a shaft. Electric motors can be powered by [[direct current]] (DC) sources, such as from batteries, motor vehicles or rectifiers, or by [[alternating current]] (AC) sources, such as a power grid, [[Inverter (electrical)|inverters]] or electrical generators. An [[electric generator]] is mechanically identical to an electric motor, but operates in the reverse direction, converting mechanical energy into electrical energy.
*'''[[Electrical engineering]]''' – Electrical engineering is an engineering discipline concerned with the study, design and application of equipment, devices and systems which use electricity, electronics, and electromagnetism.
*'''[[Electrical circuit]]''' – an electrical network consisting of a closed loop, giving a return path for the current.
*'''[[Electrical network]]''' – an interconnection of [[electronic component|electrical component]]s (e.g., [[battery (electricity)|batteries]], [[resistor]]s, [[inductor]]s, [[capacitor]]s, [[switch]]es, [[transistor]]s) or a model of such an interconnection, consisting of [[electrical element]]s (e.g., [[voltage source]]s, [[current source]]s, [[Electrical resistance and conductance|resistance]]s, [[inductance]]s, [[capacitance]]s).
*'''[[Electromagnetism]]''' –
*'''[[Electronic circuit]]''' – a type of electrical circuit which is composed of individual [[electronic component]]s, such as [[resistor]]s, [[transistor]]s, [[capacitor]]s, [[inductor]]s and [[diode]]s, connected by conductive [[wire]]s or [[Conductive trace|traces]] through which [[electric current]] can flow.
*'''[[Electronics]]''' –
*'''[[Energy]]''' –
*'''[[Engine]]''' –
*'''[[Engineering]]''' – the use of [[scientific method|scientific principles]] to design and build machines, structures, and other items.
*'''[[Engineering cybernetics]]''' –
*'''[[Engineering drawing]]''' – a type of [[technical drawing]] that is used to convey information about an object. ''Detail drawings'' commonly specify the [[dimensions]] and [[Engineering tolerance|tolerances]] for the construction of a single component, while a master drawing or ''assembly drawing'' links the detail drawings for each component in a system. Only required information is typically specified, usually only in one place to avoid inconsistency.
*'''[[Engineering economics]]''' – a subset of economics that studies the behavior of individuals and firms in making engineering decisions regarding the allocation of limited resources. It is a simplified application of [[microeconomic theory|microeconomics]] in that it assumes elements such as price determination, competition and demand/supply to be fixed inputs.
*'''[[Engineering ethics]]''' – a field that examines and sets the obligations by [[engineer]]s to [[society]], to their clients, and to the profession. Many [[List_of_engineering_societies|engineering professional societies]] have prepared codes of ethics which are largely similar to each other.
*'''[[Engineering management]]''' – the combination of technological problem-solving and the organizational, administrative, legal and planning abilities of [[management]] in order to oversee the operational performance of complex engineering driven enterprises.
*'''[[Engineering society]]''' – a [[professional organization]] for [[engineer]]s of various [[Fields of engineering|disciplines]]. Some are umbrella type organizations which accept many different disciplines, while others are discipline-specific. There are also many student-run engineering societies, commonly at universities or technical colleges.
*'''[[Exploratory engineering]]''' – the process of designing and analyzing detailed hypothetical models of systems that are not feasible with current technologies or methods, but do seem to be clearly within the bounds of what science considers to be possible. It usually results in [[prototypes]] or [[computer simulations]] that are as convincing as possible to those that know the relevant science, given the lack of experimental confirmation.

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==F==
*'''Fits and tolerances''' -
*'''[[Factor of safety]]''' –
*'''[[False precision]]''' –
*'''[[Fast fracture]]''' –
*'''[[Fatigue (material)|Fatigue]]''' –
*'''[[Fillet (mechanics)|Fillet]]''' –
*'''[[First Law of Thermodynamics]]''' – states that [[energy]] can neither be created nor destroyed; it can change only from one form to another.

*'''[[Finite element analysis]]''' –
*'''[[Flange]]''' -
*'''[[Fluid mechanics]]''' –
*'''[[Flywheel]]''' –
*'''[[Force]]''' – an influence that can push or pull an [[Physical object|object]] to change its [[motion]]. A force can cause an object with [[mass]] to change its [[velocity]] (e.g. moving from a [[Newton's first law|state of rest]]), i.e., to [[accelerate]]. A force has both [[Euclidean vector#Length|magnitude]] and [[Direction (geometry, geography)|direction]], making it a [[Vector (geometric)|vector]] quantity.
*'''[[Force density]]''' –
*'''[[Forging]]''' –
*'''[[Four-bar linkage]]''' –
*'''[[Four-stroke cycle]]''' –
*'''[[Four wheel drive]]''' –
*'''[[Friction]]''' – the [[force]] resisting the relative motion of solid surfaces, fluid layers, and material elements [[sliding (motion)|sliding]] against each other. There are several types of friction including ''static friction'' between non-moving surfaces and ''kinetic friction'' between moving surfaces; for two given solid surfaces, static friction is greater than kinetic friction. ''Fluid friction'' describes the friction between layers of a [[viscous]] fluid that are moving relative to each other.
*'''[[Front wheel drive]]''' –
*'''[[Fundamentals of Engineering exam]]''' –
*'''[[Fusible plug]]''' –
*'''[[Fusion Deposition Modelling|Fusion deposition modelling]]''' –

==G==
*'''[[Gas compressor]]''' –
*'''[[Gauge (engineering)|Gauge]]''' –
*'''[[Gear]]''' – a [[rotating]] circular [[machine element|machine part]] having cut or inserted teeth which mesh with another compatible toothed part to transmit [[torque]] and speed. Each gear tooth essentially functions as a [[lever]] with its fulcrum at the gear's center.
*'''[[Gear coupling]]''' – a mechanical device for transmitting [[torque]] between two shafts that are not [[Line (geometry)|collinear]]. It consists of a flexible joint fixed to each shaft. The two joints are connected by a third shaft, called the spindle.
*'''[[Gear ratio]]''' – the ratio of the [[pitch circles]] of mating gears which defines the speed ratio and the [[mechanical advantage]] of the gear set.
*'''[[Granular material]]''' –

==H==
*'''[[Heat engine]]''' – a system that converts heat or [[thermal energy]]—and [[chemical energy]]—to [[mechanical energy]], which can then be used to do [[mechanical work]].<ref>''Fundamentals of Classical Thermodynamics'', 3rd ed. p. 159, (1985) by G. J. Van Wylen and R. E. Sonntag: "A heat engine may be defined as a device that operates in a thermodynamic cycle and does a certain amount of net positive work as a result of heat transfer from a high-[[temperature]] body and to a low-temperature body. Often the term heat engine is used in a broader sense to include all devices that produce work, either through heat transfer or combustion, even though the device does not operate in a thermodynamic cycle. The internal-combustion engine and the gas turbine are examples of such devices, and calling these heat engines is an acceptable use of the term."</ref><ref>''Mechanical efficiency of heat engines'', p. 1 (2007) by James R. Senf: "Heat engines are made to provide mechanical energy from thermal energy."</ref> 
*'''[[Heat transfer]]''' –
*'''[[HVAC|Heating and cooling systems]]''' –
*'''[[Hinge]]''' –
*'''[[Hoberman mechanism]]''' –
*'''[[Hobson's joint]]''' –
*'''[[Hooke's law]]''' –
*'''[[Hotchkiss drive]]''' –
*'''[[HVAC]]''' –
*'''[[Hydraulics]]''' –
*'''[[Hydrostatics]]''' –

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==I==
*'''[[Ideal machine]]''' –
*'''[[Ideal mechanical advantage]]''' –
*'''[[Imperial College London]]''' –
*'''[[Inclined plane]]''' –
*'''[[Independent suspension]]''' –
*'''[[Inductor]]''' –
*'''[[Industrial engineering]]''' –
*'''[[Inertia]]''' –
*'''[[Institution of Mechanical Engineers]]''' –
*'''[[Instrumentation]]''' –
*'''[[Integrated circuit]]''' –
*'''[[Intelligent pump]]''' –
*'''[[Invention]]''' – a unique or novel device, method, composition, idea or process. An ''inventor'' who creates or discovers a new invention can sometimes receive a [[patent]], or legal right to exclude others from making, using, or selling that invention for a limited time.


==J==
*'''[[Jack chain]]''' –
*'''[[Jacking gear]]''' –
*'''[[JIC fitting]]''' –
*'''[[Joule]]''' – the [[SI]] unit of [[energy]], which uses the symbol ''J''. It is equal to the amount of [[Work (physics)|work]] done when a force of 1 [[Newton (unit)|newton]] displaces a mass through a distance of 1 [[metre]] in the direction of the force applied. It is also the energy dissipated as heat when an [[electric current]] of one [[ampere]] passes through a [[Electrical resistance and conductance|resistance]] of one [[ohm]] for one second.

==K==
*'''[[Kelvin]]''' – the primary [[SI]] unit of [[temperature]], which uses the symbol ''K'' and has [[absolute zero]] as its zero point. The temperature in [[degree Celsius]] is defined as the temperature in kelvins minus 273.15 (i.e. 0 °C is equal to 273.15 K).
*'''[[Kinematic determinacy]]''' –
*'''[[Kinematics]]''' –

==L==
*'''[[Laser]]''' –
*'''[[Leaf spring]]''' –
*'''[[Lever]]''' – a [[simple machine]] consisting of a [[beam (structure)|beam]] or rigid rod pivoted at a fixed [[hinge]], or ''fulcrum''. A lever amplifies an input force to provide a greater output force, which is said to provide ''leverage''. The ratio of the output force to the input force is the [[mechanical advantage]] of the lever.
*'''[[Legal liability|Liability]]''' –
*'''[[Life cycle assessment|Life cycle cost analysis]]''' –
*'''[[Limit state design]]''' –
*'''[[Linkage (mechanical)|Linkage]]''' –
*'''[[Live axle]]''' –
*'''[[Load transfer]]''' –
*'''[[Locomotive]]''' –
*'''[[Lubrication]]''' –

{{Compact ToC|side=yes|center=yes|top=yes|num=yes|extlinks=yes|seealso=yes|refs=yes|nobreak=yes|}}

==M==
*'''[[Machine]]''' –
*'''[[Machine learning]]''' –
*'''[[Machinery's Handbook]]''' – a classic, one-volume reference work in mechanical engineering and practical [[workshop]] [[mechanic]]s published by [[Industrial Press]], New York, since 1914; its 31st edition was published in 2020. Recent editions of the handbook contain chapters on mathematics, mechanics, materials, measuring, toolmaking, manufacturing, threading, gears, and machine elements, combined with excerpts from [[American National Standards Institute|ANSI]] standards. 
*'''[[Magnetic circuit]]''' –
*'''[[Factor of safety|Margin of safety]]''' –
*'''[[Mass transfer]]''' –
*'''[[Materials science|Materials]]''' –
*'''[[Materials engineering]]''' –
*'''[[Material selection]]''' –
*'''[[Mechanical advantage]]''' –
*'''[[Mechanical Biological Treatment|Mechanical biological treatment]]''' –
*'''[[Mechanical efficiency]]''' –
*'''[[Mechanical engineering]]''' –
*'''[[Mechanical equilibrium]]''' –
*'''[[Mechanical work]]''' –
*'''[[Mechanics]]''' –
*'''[[Mechanochemistry]]''' –
*'''[[Mechanosynthesis]]''' –
*'''[[Mechatronics]]''' –
*'''[[Microelectromechanical systems]]''' –
*'''[[Micromachinery]]''' –
*'''[[Microprocessor]]''' –
*'''[[Microtechnology]]''' –
*'''[[Modulus of rigidity]]'''--
*'''[[Molecular assembler]]''' –
*'''[[Molecular nanotechnology]]''' –
*'''[[Moment (physics)|Moment]]''' –
*'''[[Moment of inertia]]''' –
*'''[[Motorcycle]]''' –
*'''[[Multi-link suspension]]''' –

==N==
*'''[[Nanotechnology]]''' –
*'''[[Newton (unit)]]''' – the [[SI]] unit of [[force]], which uses the symbol ''N''. It is defined as 1 kg⋅m/s{{sup|2}}, the force which gives a mass of 1 kilogram an acceleration of 1 metre per second per second. It is named after [[Isaac Newton]] in recognition of his work on [[classical mechanics]], specifically [[Newton's laws of motion#Newton's second law|Newton's second law of motion]].

*'''[[Normal stress]]''' –
*'''[[Nozzle]]''' –

==O==
*'''[[Ohm's law]]''' – states that the [[electric current|current]] through a [[Electrical conductor|conductor]] between two points is directly [[Proportionality (mathematics)|proportional]] to the [[voltage]] across the two points. It is typically expressed as the equation {{math|''I''}} = ''V'' ÷ ''R'', where {{math|''I''}} is the current through the conductor, ''V'' is the voltage measured ''across'' the conductor and ''R'' is the [[electrical resistance|resistance]] of the conductor.
*Orientation
*'''[[Overdrive (mechanics)|Overdrive]]''' –
*'''[[Oversteer]]''' –

==P==
*'''[[Pascal (unit)]]''' – the [[SI]] unit of [[pressure]], which uses the symbol ''Pa'' and is defined as one [[Newton (unit)|newton]] per square metre. It is also used to quantify [[internal pressure]], [[stress (physics)|stress]], [[Young's modulus]], and [[ultimate tensile strength]].
*'''[[Physics]]''' –
*'''[[Pinion]]''' –
*'''[[Piston]]''' –
*'''[[Pitch drop experiment]]''' –
*'''[[Plain bearing]]''' –
*'''[[Plasma processing]]''' –
*'''[[Plasticity (physics)|Plasticity]]''' –
*'''[[Pneumatics]]''' –
*'''[[Poisson's ratio]]''' –
*'''[[Position vector]]''' –
*'''[[Potential difference]]''' –
*'''[[Power (physics)|Power]]''' – the amount of [[energy]] transferred or converted per unit time. Power is a [[Scalar (physics)|scalar]] quantity.
*'''[[Power stroke (engine)|Power stroke]]''' –
*'''[[Pressure]]''' –
*'''[[Process control]]''' –
*'''[[Product Lifecycle Management|Product lifecycle management]]''' –
*'''[[Professional engineer]]''' ('''PE''') – In the United States, this designation is given to engineers who have passed the [[Principles and Practice of Engineering exam]], or PE exam. Upon passing the PE exam and meeting other eligibility requirements, that vary by state, such as education and experience, an engineer can then become registered in their State to stamp and sign engineering drawings and calculations as a PE.
*'''[[Project management]]''' –
*'''[[Pulley]]''' –
*'''[[Pump]]''' –

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==Q==
*'''[[Quality (business)|Quality]]''' –
*'''[[Quality control]]''' –
*'''[[Quality assurance]]''' –

==R==
*'''[[Rack and pinion]]''' –
*'''[[Rack railway]]''' –
*'''[[Railcar]]''' –
*'''[[Rail gauge]]''' –
*'''[[Railroad car]]''' –
*'''[[Railroad switch]]''' –
*'''[[Rail tracks]]''' –
*'''[[Random vibration]]''' –
*'''[[Reaction kinetics]]''' –
*'''[[Rear wheel drive]]''' –
*'''[[Refrigeration]]''' –
*'''[[Reliability engineering]]''' –
*'''[[Relief valve]]''' –
*'''[[RepRap Project]]''' –
*'''[[Friction|Resistive force]]''' –
*'''[[Resistor]]''' –
*'''[[Reverse engineering]]''' –
*'''[[Rheology]]''' –
*'''[[Rigid body]]''' –
*'''[[Robotics]]''' –
*'''[[Roller chain]]''' –
*'''[[Rolling]]''' –
*'''[[Rotordynamics]]''' –
*'''[[Rube Goldberg machine]]''' –

{{Compact ToC|side=yes|center=yes|top=yes|num=yes|extlinks=yes|seealso=yes|refs=yes|nobreak=yes|}}

==S==
*'''[[Safety engineering]]''' –
*'''[[Screw theory]]''' –
*'''[[Seal (mechanical)|Seal]]''' –
*'''[[Second Law of Thermodynamics]]''' – states that when [[energy]] changes from one form to another form, or matter moves freely, [[entropy]] (disorder) in a closed system increases. In other words, heat always moves from hotter objects to colder objects unless energy is supplied to reverse the direction of [[heat flow]], and not all heat energy can be converted into [[Work (thermodynamics)|work]] in a [[cyclic process]].
*'''[[Semiconductor]]''' –
*'''[[Series and parallel circuits]]''' –
*'''[[Shear force]] [[diagram]]s''' –
*'''[[Shear pin]]''' –
*'''[[Shear strength]]''' –
*'''[[Shear stress]]''' –
*'''[[Simple machine]]''' –
*'''[[Simulation]]''' –
*'''[[Slide rule]]''' –
*'''[[Society of Automotive Engineers]]''' –
*'''[[Solid mechanics]]''' –
*'''[[Solid modeling]]''' –
*'''[[Split nut]]''' –
*'''[[Sprung mass]]''' –
*'''[[Statics]]''' –
*'''[[Steering]]''' –
*'''[[Stress–strain curve]]''' – a chart which gives the relationship between [[stress (mechanics)|stress]] and [[Deformation (physics)#Strain|strain]] for a given material. It is obtained by gradually applying [[Structural load|load]] to a test coupon and measuring the [[Deformation (engineering)|deformation]].
*'''[[Structural failure]]''' –
*'''[[Student Design Competition]]''' –
*'''[[Surveying]]''' –
*'''[[Suspension (vehicle)|Suspension]]''' –
*'''[[Switch]]''' – an [[electrical component]] that can disconnect or connect the conducting path in an [[electrical circuit]], interrupting the [[electric current]] or diverting it from one conductor to another.

{{Compact ToC|side=yes|center=yes|top=yes|num=yes|extlinks=yes|seealso=yes|refs=yes|nobreak=yes|}}

==T==
*'''[[Technical drawing]]''' – the act and [[Academic discipline|discipline]] of composing [[Plan (drawing)|drawings]] that [[Visual communication|visually communicate]] how something functions or is constructed. In [[Manufacturing|industry]] and [[engineering]], common [[Convention (norm)|conventions]] constitute a [[visual language]] and help to ensure that the drawing is precise, [[unambiguous]] and relatively easy to understand. Many of the symbols and principles of technical drawing are codified in an [[international standard]] called [[ISO 128]].
*'''[[Technology]]''' – refers to both the application of [[knowledge]] for achieving practical [[goal]]s in a [[Reproducibility|reproducible]] way, and the products and [[tools]] resulting from such efforts.
*'''[[Tensile strength]]''' – also called ''ultimate tensile strength'' or ''ultimate strength'', is the maximum [[stress (mechanics)|stress]] that a material can withstand while being stretched or pulled before breaking. In [[brittle failure|brittle]] materials the ultimate tensile strength is close to the [[yield point]], whereas in [[ductility|ductile]] materials the ultimate tensile strength can be higher.
*'''[[Tensile stress]]''' –
*'''[[Testing Adjusting Balancing|Testing adjusting balancing]]''' –
*'''[[Theory of elasticity]]''' –
*'''[[Thermodynamics]]''' – a branch of [[physics]] that deals with [[heat]], [[Work (thermodynamics)|work]], and [[temperature]], and their relation to [[energy]], [[entropy]], and the physical properties of [[matter]] and [[radiation]]. The behavior of these quantities is governed by the four [[laws of thermodynamics]].
*'''[[Third Law of Thermodynamics]]''' – states that the [[entropy]] of a system approaches a constant value when its temperature approaches [[absolute zero]], because its [[atoms]] would stop moving. However, [[heat transfer]] between the system and its surroundings would prevent the system from ever reaching absolute zero.
*'''[[Toe (automotive)|Toe]]''' –
*'''[[Torque]]''' –
*'''[[Torsion beam suspension]]''' –
*'''[[Torsion spring]]''' –
*'''[[Toughness]]''' –
*'''[[Track gauge]]''' – Spacing of the rails on a railway track
*'''[[Transmission (mechanics)|Transmission]]''' –
*'''[[Truck]]''' –
*'''[[Bogie|Truck (railway)]]''' – Chassis for wheels and suspension under railway vehicles, ''bogie'' outside U.S.
*'''[[Turbine]]''' –
*'''[[Tribology]]''' –
*'''[[Touch screen]]''' –
*'''[[Tearing|tear]]''' –
*'''[[Tire manufacturing]]''' –

{{Compact ToC|side=yes|center=yes|top=yes|num=yes|extlinks=yes|seealso=yes|refs=yes|nobreak=yes|}}

==U==
*'''[[Understeer]]''' –
*'''[[Unibody]]''' –
*'''[[Unsprung weight]]''' –

==V==
* '''[[Verification and Validation]]''' –
* '''[[Valve]]''' – a device or natural object (such as a [[heart valve]]) that regulates, directs or controls the flow of a fluid (gases, liquids, fluidized solids, or [[slurries]]) by opening, closing, or partially obstructing various passageways
* '''[[Vector (geometric)|Vector]]''' – a geometric object that has [[Magnitude (mathematics)|magnitude]] (or [[euclidean norm|length]]) and [[Direction (geometry)|direction]]. A ''vector quantity'' is differentiated from a ''scalar quantity'' which only has magnitude, not direction. Vectors can be added to other vectors according to [[Vector calculus|vector algebra]].
* '''Vertical strength''' –
* '''[[Viscosity]]''' –
* '''[[Volt]]''' – the [[SI]] unit of [[electric potential]], [[electric potential difference]] ([[voltage]]), and [[electromotive force]], which uses the symbol ''V''.
* '''[[Vibration]]''' –
* '''Velocity diagrams''' –

==W==
*'''[[Wear]]''' – is the damaging, gradual removal or deformation of material at [[Solid|solid surfaces]]. Causes of wear can be mechanical (e.g., [[erosion]]) or [[Chemistry|chemical]] (e.g., [[corrosion]]). The study of wear and related processes is referred to as [[tribology]].
*'''[[Wedge (mechanics)|Wedge]]''' – a [[triangle|triangular]] shaped tool, and is a portable [[inclined plane]], and one of the six classical [[simple machine]]s. It can be used to separate two objects or portions of an object, lift up an object, or hold an object in place. It functions by converting a [[force]] applied to its blunt end into forces perpendicular ([[Surface normal|normal]]) to its inclined surfaces. <!-- this link is broken <ref>{{Citation | title = Wedges and screws | url = http://em-ntserver.unl.edu/Negahban/em223/note16/note16.htm | access-date = 2009-07-29}}.</ref> --> The [[mechanical advantage]] of a wedge is given by the ratio of the length of its slope to its width.<ref name="bowser">{{Citation | last = Bowser | first = Edward Albert | title = An elementary treatise on analytic mechanics: with numerous examples | publisher = D. Van Nostrand Company | pages= 202–203 | year = 1920 | edition = 25th | url = https://books.google.com/books?id=mE4GAQAAIAAJ}}.</ref><ref name="CEST">''McGraw-Hill Concise Encyclopedia of Science & Technology'', Third Ed., Sybil P. Parker, ed., McGraw-Hill, Inc., 1992, p. 2041.</ref> Although a short wedge with a wide angle may do a job faster, it requires more force than a long wedge with a narrow angle.
*'''[[Weight transfer]]''' –
*'''[[Wheel]]''' – In its primitive form, a wheel is a circular block of a hard and durable material at whose center has been bored a hole through which is placed an [[axle]] [[bearing (mechanical)|bearing]] about which the wheel rotates when [[torque]] is applied to the wheel about its axis. The [[wheel and axle]] assembly can be considered one of the [[Simple machine|six simple machines]].
*'''[[Wheel and axle]]''' – a machine consisting of a [[wheel]] attached to a smaller [[axle]] so that these two parts rotate together in which a force is transferred from one to the other. The wheel and axle can be viewed as a version of the lever, with a drive force applied tangentially to the perimeter of the wheel and a load force applied to the axle, respectively, that are balanced around the hinge which is the fulcrum.
*'''[[Wheelset (railroad)|Wheelset]]''' – the [[Train wheel|wheel]]–[[Axle#Vehicle axles|axle]] assembly of a [[railroad car]].  The frame assembly beneath each end of a car, [[railcar]] or [[locomotive]] that holds the wheelsets is called the [[bogie]] (or truck in [[North America]]). Most North American [[Railroad car#Freight cars|freight cars]] have two bogies with two or three wheelsets, depending on the type of car; short [[Goods wagon|freight cars]] generally have no bogies but instead have two wheelsets.
*'''[[Work (physics)|Work]]''' – the [[energy]] transferred to or from an object via the application of [[force]] along a [[Displacement (vector)|displacement]]. Work is a [[Scalar (physics)|scalar]] quantity.

==X==
*'''X bar charts'''

==Y==
*'''[[Yield point]]''' – In [[materials science]] and [[engineering]], the yield point is the point on a [[stress–strain curve]] that indicates the limit of [[Elasticity (physics)|elastic]] behavior and the beginning of [[Plasticity (physics)|plastic]] behavior. Below the yield point, a material will [[Deformation (engineering)#elastic deformation|deform elastically]] and will return to its original shape when the applied [[Stress (mechanics)|stress]] is removed. Once the yield point is passed, some fraction of the deformation will be permanent and non-reversible and is known as [[Deformation (engineering)#plastic deformation|plastic deformation]].
*'''[[Yield strength]]''' – or ''yield stress'', is a [[List of materials properties|material property]] and is the stress corresponding to the yield point at which the material begins to deform plastically. The yield strength is often used to determine the maximum allowable [[Structural load|load]] in a mechanical component, since it represents the upper limit to forces that can be applied without producing permanent deformation. In some materials, such as [[aluminium]], there is a gradual onset of non-linear behavior, making the precise yield point difficult to determine. In such a case, the offset yield point (or ''proof stress'') is taken as the stress at which 0.2% plastic deformation occurs. Yielding is a gradual [[Failure cause|failure mode]] which is normally not [[catastrophic failure|catastrophic]], unlike [[ultimate failure]].
*'''[[Young's modulus]]''' – Young's modulus <math>E</math>, the ''Young modulus'' or the [[modulus of elasticity]] in tension, is a mechanical property that measures the tensile [[stiffness]] of a [[solid]] material. It quantifies the relationship between tensile [[stress (mechanics)|stress]] <math>\sigma</math> (force per unit area) and axial [[strain (mechanics)|strain]] <math>\varepsilon</math> (proportional deformation) in the [[linear elasticity|linear elastic]] region of a material and is determined using the formula:<ref>{{cite book |title=Nature and Properties of Engineering Materials |first=D. |last=Jastrzebski |publisher=John Wiley & Sons, Inc |edition=Wiley International |year=1959}}</ref>

::<math>E=\frac{\sigma}{\varepsilon}</math>

:Young's moduli are typically so large that they are expressed not in [[Pascal (unit)|pascals]] but in gigapascals (GPa).

==Z==
*'''[[Zero Defects|Zero defects]]''' – (or ''ZD''), was a management-led program to eliminate defects in industrial production that enjoyed brief popularity in American industry from 1964<ref>{{cite book | title = A Guide to Zero Defects: Quality and Reliability Assurance Handbook | year = 1965 | publisher = [[United States Assistant Secretary of Defense|Office of the Assistant Secretary of Defense]] (Manpower Installations and Logistics) | location = Washington, D.C. | id = 4155.12-H | oclc = 7188673 | url = https://apps.dtic.mil/sti/citations/ADA950061 | access-date = May 29, 2014 | page = 3 | quote = Early in 1964 the Assistant Secretary of Defense (Installations and Logistics) invited the attention of the Military Departments and the [[Defense Logistics Agency|Defense Supply Agency]] to the potential of Zero Defects.  This gave the program substantial impetus.  Since that time Zero Defects has been adopted by numerous industrial and Department of Defense activities. | archive-date = May 29, 2014 | archive-url = https://web.archive.org/web/20140529122504/http://www.dtic.mil/docs/citations/ADA950061 | url-status = live }}</ref> to the early 1970s.  Quality expert [[Philip B. Crosby|Philip Crosby]] later incorporated it into his "Absolutes of Quality Management" and it enjoyed a renaissance in the American automobile industry—as a performance goal more than as a program—in the 1990s.  Although applicable to any type of enterprise, it has been primarily adopted within [[supply chain]]s wherever large volumes of components are being purchased (common items such as nuts and bolts are good examples).
*'''[[Zeroth Law of Thermodynamics]]''' – If body A is in thermal equilibrium (no heat transfers between them when in contact) with body C, and body B is in thermal equilibrium with body C, then A is in thermal equilibrium with B.

{{Compact ToC|side=yes|center=yes|top=yes|num=yes|extlinks=yes|seealso=yes|refs=yes|nobreak=yes|}}

==See also==
*[[Mechanical engineering]]
*[[Engineering]]
*[[Glossary of engineering]]
*[[National Council of Examiners for Engineering and Surveying]]
*[[Fundamentals of Engineering Examination]]
*[[Principles and Practice of Engineering Examination]]
*[[Graduate Aptitude Test in Engineering]]
*[[Glossary of aerospace engineering]]
*[[Glossary of civil engineering]]
*[[Glossary of electrical and electronics engineering]]
*[[Glossary of structural engineering]]
*[[Glossary of areas of mathematics]]
*[[Glossary of artificial intelligence]]
*[[Glossary of astronomy]]
*[[Glossary of automotive design]]
*[[Glossary of biology]]
*[[Glossary of calculus]]
*[[Glossary of chemistry terms|Glossary of chemistry]]
*[[Glossary of economics]]
*[[Glossary of physics]]
*[[Glossary of probability and statistics]]

==References==
{{reflist}}

===Works cited===
{{refbegin|2}}
* {{cite arXiv |last1=Legg |first1=Shane |last2=Hutter |first2=Marcus |date=15 June 2007 |title=A Collection of Definitions of Intelligence |class=cs.AI |eprint=0706.3639}}
* {{Citation |last1=Low |first1=David Allan |last2=Bevis |first2=Alfred William |title=Manual of machine drawing and design |publisher=Longmans, Green, and co |year=1908 |edition=Revised |url=https://books.google.com/books?id=acYJAAAAIAAJ}}. 
* {{cite book |last=Nilsson |first=Nils |author-link=Nils Nilsson (researcher) |year=1998 |title=Artificial Intelligence: A New Synthesis |url=https://archive.org/details/artificialintell0000nils |url-access=registration |publisher=Morgan Kaufmann |isbn=978-1-55860-467-4 |access-date=18 November 2019 |archive-date=26 July 2020 |archive-url=https://web.archive.org/web/20200726131654/https://archive.org/details/artificialintell0000nils |url-status=live}}
* {{Citation |last=Oleson |first=John Peter |year=2000 |contribution=Water-Lifting |editor-last=Wikander |editor-first=Örjan |editor-link=Örjan Wikander |title=Handbook of Ancient Water Technology |series=Technology and Change in History |location=Leiden |volume=2 |pages=217–302 (242–251) |isbn=90-04-11123-9}}
* {{Russell Norvig 2003}}.
* {{Cite book |first1=Stuart J. |last1=Russell |first2=Peter |last2=Norvig |title=[[Artificial Intelligence: A Modern Approach]] <!-- |url=http://aima.cs.berkeley.edu/ --> |year=2009 |edition=3rd |publisher=Prentice Hall |location=Upper Saddle River, New Jersey |isbn=978-0-13-604259-4 |author-link=Stuart J. Russell |author2-link=Peter Norvig}}.
* {{cite book |first1=David |last1=Poole |author-link=David Poole (researcher) |first2=Alan |last2=Mackworth |author2-link=Alan Mackworth |first3=Randy |last3=Goebel |author3-link=Randy Goebel |year=1998 |title=Computational Intelligence: A Logical Approach |publisher=Oxford University Press |location=New York |isbn=978-0-19-510270-3 |url=https://archive.org/details/computationalint00pool |access-date=22 August 2020 |archive-date=26 July 2020 |archive-url=https://web.archive.org/web/20200726131436/https://archive.org/details/computationalint00pool |url-status=live}}
* {{Citation |last=Smith |first=Carroll |author-link=Carroll Smith |title=Carroll Smith's Nuts, Bolts, Fasteners, and Plumbing Handbook |publisher=MotorBooks/MBI Publishing Company |year=1990 |url=https://books.google.com/books?id=A81HmmRCN7YC |isbn=0-87938-406-9}}.
{{refend}}

{{Engineering fields}}
{{Glossaries of science and engineering}}

[[Category:Mechanical engineering]]
[[Category:Indexes of engineering topics|Mechanical engineering topics]]
[[Category:Glossaries of science|mechanical engineering]]
[[Category:Glossaries of technology|Mechanical engineering]]
[[Category:Wikipedia glossaries using unordered lists]]