1.Material:Y40um /1144 2.Hardness:HRC45-50 3.Technology:straight knurling .milling groove 4.Surface treatment:Carb 1.Material:Y40um /11442.Hardness:HRC45-°-50°3.Surface treatment:Carburization4.Technology:straight knurling .milling groove(groove depth:0.01mm-0.1mm)5.Surface roughness:0.02μm6.size tolerance:±0.01mm7.Diameter:8mm8.length:78mm Pin shaft