| Abrasion-Resistant Steels | (english) A family of steel products developed for those applications involved in sliding and/or impact abrasion. |
| Abrasive 2 | (english) Natural – sandstone,emery,corundum,diamonds, or Artificial – silicon carbide,aluminum oxide – material used for making grinding wheels,andpaper,abrasive and lapping compunds. |
| ACCUMULATOR | (english) A vessel, normally cylindrical, which is used to store fluid and gas for future release of the energy in the compressed fluid and gas. Normally contains a diaphragm or piston between the fluid (liquid) and gas chambers. Fluid is normally introduced at one end and the gas at the opposite end. |
| Adapters | (english) Steel segments that are bolted to the reel mandrel to increase their diameter so that large (24" ID) coils can be run. |
| Addendum | (english) That portion of a gear tooth that extends from the pitch circle to the outside diameter. |
| AFS Tests | (english) A number of standard tests determined by American Foundrymen's Society to evaluate molding and core sands. |
| Aging 1 | (english) A change in the properties of certain metal and alloys (such as steel) that occurs at ambient or moderately elevated temperatures after a hot working heat treatment or cold working operation. Typical properties impacted are hardness, yield strength, tensile strength, ductility, impact value, formability, magnetic properties, etc. See also Non-aging. |
| Aging 2 | (english) A change in properties that occurs at ambient or moderately elevated temperatures after hot working or a heat treating operation (quench aging in ferrous alloys), or after a cold working operation (strain aging). The change in properties is often, but not always, due to a phase change (precipitation), but does not involve a change in chemical composition. In a metal or alloy, a change in properties that generally occurs slowly at room temperature and more rapidly at higher temperatures. |
| B Elevation | (english) The bottom level of the boiler firebox where two oil guns are located. The oil guns are used if the boiler needs extra steam while on oil fire. |
| BACK PRESSURE | (english) The level of pressure on the return or downstream side of a device or system. |