| A Sheet Metal Screw | (english) Sheet metal screws with (a) sharp-pointed ends; and (b) fewer threads per inch than type AB screws; and (c) deeper threads with bettere gripping power than type AB. The industrial Fasteners Institue incorrectly labes type A an “obsolete” thread though it is universally preferred in 18-8 stainless over type AB, especially by the marine industry. |
| 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. |
| 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. |
| 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 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. |
| 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. |
| 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. |
| AIR BLEEDER AUTOMATIC | (english) A valve that is fit into a hydraulic pipeline to facilitate automatic release of air trapped in the pipeline. See also AIR BLEEDER, MANUAL. |
| Back Gears | (english) Gears fitted to a machine to increase the number of spindle speeds obtainable with a cone or step pulley belt drive. |