1.BW664200100 grinding gear for OEM part 2.Material:20MnCr5,8620H,20CrMoH ... hardness:60-61 HRC 4.Core hardness:36 HRC Our BW664200100 grinding gear can be manufactured according the design from customers ... to have excellent control on the deformation during heat treatment. BW664200100 grinding gear: Number of teeth: 31 Standard module:2.5 ...