| undeformed state | สถานะคงรูป |
| uniformity | ความสม่ำเสมอ |
| uniform load | น้ำหนักบรรทุกชนิดแผ่สม่ำเสมอ |
| uniform sand | ทรายขนาดเดียว |
| 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 |
| Ac1 | (english) The temperature at which austenite begins to form on heating. |
| Ac3 | (english) In hypoeutectoid steel, the temperature at which transformation of ferrite into austenite is completed upon heating. |
| 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. |
| Accurate | (english) Conforms to a standard or tolerance. |
| 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. |