Base material:
(1) 38CrMoAlA(JIS SACM645)
(2) 42CrMo(AISI 4140)
Process:
1.Heat treatment
2.Nitriding treatment
Technical Parameters:
1.nitriding depth: 0.4mm-0.6mm
2.nitriding hardness: 850-950HV
3.nitriding brittleness:<=1
4.the surface roughness:Ra0.4
5.screw straightness: 0.015mm