The material is 20Mn or 40Cr.

As for the 20Mn,

It adopt carburization and quench hardening.

The carburized depth is 0.8~1.2mm, and the surface hardening is HRC53-58, 40Cr adopt whole quench hardening, after tempering, the hardening is HRC45-48,

The surface is treated with phosphating, specification can be customized,