Selected Material Carbon Steel SAE1020, SAE1045, Cr12, 40Cr, Y15Pb, 1214L, etc. Alloy Steel 20CrMnTi, 16MnCr5, 20CrMnMo, 41CrMo, 17CrNiMo5, etc. Brass / Bronze HPb59-1, H70, CuZn39Pb2, CuZn40Pb2, C38000, CuZn40, etc. Modules 1.0, 1.25, 1.5, 1.75, 2.0, 2.25, 2.5….8.0, etc. Machining Process Gear Hobbing, Gear Milling, Gear Shaping, Gear Broaching, Gear Shaving, Gear Grinding and Gear Lapping. Heat Treatments Quenching & Tempering, Carburizing & Quenching, High-frequency Hardening, Carbonitriding…… Surface Treatment Blacking, Polishing, Anodization, Chrome Plating, Zinc Plating, Nickel Plating…… Teeth Accuracy DIN Class 4, ISO/GB Class 4, AGMA Class 13, JIS Class 0 Tolerance Control Outer Diameter ±0.005 mm Length Dimension ±0.05 mm