| Acid | (english) 1) A solution or liquid with a pH less than 7, 2) term applied to slags, refractors, and minerals containing a high percentage of silica. |
| Acid Brittleness (Pickling Brittleness) | (english) Brittleness resulting from pickling steel in acid; hydrogen, formed by the interaction between iron and acid, is partially absorbed by the metal, causing acid brittleness. |
| Acid Process 1 | (english) A process of making steel, either Bessemer, open-hearth or electric, in which the furnace is lined with a siliceous refractory and for which low phosphorus pig iron is required as this element is not removed. |
| Acid Process 2 | (english) A steel making method using an acid refractory-lined (usually silica) furnace. Neither sulfur or phosphorus is removed. |
| Acid-Brittleness | (english) Brittleness resulting from pickling steel in acid; hydrogen, formed by the interaction between iron and acid, is partially absorbed by the metal, causing acid brittleness. |
| Acid-Process | (english) A process of making steel, either Bessemer, open-hearth or electric, in which the furnace is lined with a siliceous refractory and for which low phosphorus pig iron is required as this element is not removed. |
| Activation | (english) The changing of the passive surface of a metal to a chemically active state. Contrast with passivation. |
| ADAPTER | (english) A mechanical device used to align the shaft of an electric motor (or other rotary device) with the shaft of a hydraulic pump to maintain radial and parallel shaft alignment. |
| Adapters | (english) Steel segments that are bolted to the reel mandrel to increase their diameter so that large (24" ID) coils can be run. |
| Adapti Investment Casting Process | (english) A lost wax process employing one of three methods; centrifugal, vacuum or gravity-pouring casting. |