... a. use imported EAF machine b. pass the US test c. excellent quality d. prompt delivery High speed steel ... oil cooling or air coolingNormal temper temperation: 540-560oCRC Rockwell Hardness after hardening and temper: 63-66 Characteristic:Tungsten-molybdenum ... developed by China, high performance in toughness , ,hardness, high temperature hardness.Application: Can be used in the manufacture of high ...