Special alloy steel used for high-speed cutting and turning tools, as lathe bits; so named because any tools made of it are able to remove metal much faster than tools of ordinary steel.

Operates between 60-110 psig depending upon brand. Uses high pressure and divergency to produce 10-15% faster cutting speeds.

High voltage power supplied to the plasma torch, which breaks down the air gap between the nozzle and electrode in order to initiate the plasma stream.

(as applied to gas-tungsten arc welding) An alternating current consisting of over 50,000 cycles per second at high voltage, low amperage that is superimposed on the welding circuit in GTAW power sources. It ionizes a path for non-touch arc starting and stabilizes the arc when welding with alternating current.

Steel with carbon content usually below 1.3% carbon, but may range from 1.0-2.0%.