screw barrel, Base Material : 38CrMoA1A; Technic: PTA Welding (Ni-Base) Plasma Nitriding; screw and barrel ,screw and barrel for pvc,According to the customer demands to make screws and barrelsMaterial: Alloy Steel of High Quality1) 38CrMoAlA(JIS SACM 645)2) 42CrMo(AISI 4140)3) Cr12MOV(JIS SKD11)4) 4Cr5MoSiV1(JIS SKD61) Kinds:1.Nomal screw and barrel: Nitriding screw and barrel 2,Highly wear ...