... the inner hole centrifugal casting GHII3 nature hard after high temperatureMaterial of screw raw material The finished product processing requirements38CrMoAlA,SACM645,42CrMoNitriding ... type, separation type, exhaust type, pin type, mixed type, double- head type, three-head type, multi head type etc.scope of application : PVCwood-plastic., PE wood-plastic,,Super high ...