| 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. |
| 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. |
| 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. |
| 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). |
| Acetyl Tributyl Citrate | (english) One of the lubricating oils generally applied on tin Mill Products (tin plate, TFS-chrome/chrome oxide coated steel, and blackplate). |
| Acid Steel | (english) Steel melted in a furnace with an acid bottom and lining and under a slag containing an excess of an acid substance such as silica. |
| Adapti Investment Casting Process | (english) A lost wax process employing one of three methods; centrifugal, vacuum or gravity-pouring casting. |
| Addendum | (english) That portion of a gear tooth that extends from the pitch circle to the outside diameter. |
| Adeline Steelmaking Process | (english) Method of producing a precision casting of steel or steel alloys using aluminolthermic process and lost wax, followed by centrifugal action. |