Tool Steel Drill Rod A2 is an air-hardening tool steel with good strength and with excellent stability in heat treatment. A-2 tool steel exhibits wear resistance that falls between O-1 and D-2 steel. A2 tool steel is well suited for cold work tooling applications and is also used for plastic molds requiring high wear resistance. Tool steel drill rod is ground and polished to a surface finish of 16 Ra and 100% free of decarburization.