| A Elevation | (English) The top level of the boiler firebox where four oil guns are located. The oil guns are used to produce steam and maintain pressure while the boiler is on oil fire. |
| AB Srews | (english) Sheet metal screws with pointed ends similar to type-A screws and thread dimensions similar to type-B. Type AB screws are seldom used in stainless. |
| Abrasion 1 | (english) The displacement and/or detachment of metallic particles from a surface as a consequence of being exposed to flowing solids, fluids or gases. The process of rubbing, grinding, or wearing away by friction. |
| Abrasion-Resistant Steels | (english) A family of steel products developed for those applications involved in sliding and/or impact abrasion. |
| Abrasive 1 | (english) Material for grinding, polishing, blasting, either in loose form or bonded to form wheels, bricks, or files, or applied to paper and cloth by glue or resin. Natural abrasives include emery, corundum, garnet, sand, flint, etc. Metallic shot and grit are also used as abrasives in cleaning castings |
| 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. |
| Abrasive Wear | (english) The displacement and / or detachment of metallic particles from a surface as a consequence of being exposed to flowing fluids or gases. |
| Abrasive Wheels | (english) Wheels of a hard abrasive, such as Carborundum used for grinding. |
| ABSOLUTE PRESSURE | (english) The indicated value of the weight of the earth's atmosphere. At sea level, this value is approximately 14.65 psi (pounds per square inch). |
| Accordion Reed Steel | (english) Hardened, tempered, polished and blued or yellow flat steel with dressed edges. Carbon content about 1.00. Material has to possess good flatness, uniform hardness and high elasticity. |