1.Standards: ISO /DIN /ANSI 2.Model: 40SB,50SB,60SB,80SB 3.Materials:Carbon steel 40Mn 1.All parts are heat treatment(quenching and tempering) and controlled in a reasonable tolerance range.2.Tensile strength:15-20% higher than the standard3.Certificate of Quality: ISO 9001:2000,SGS 4.Centreless grinding.5.Good lubrication with excellent grease.6.Color:self,dark yellow,dark blue,black