... .all products are made in our own factory Steel Stock Spur Gearswe produce all types and sizes ... 10. Outer diameter: 6~800mm Material: Mild steel, cast steel, cast iron, forged steel, stainless steel, alloy steel, plasitc, POM, aluminium alloy, zn alloy ... , bronze, brass, chrome, 40Cr, 20CrMnTi, Steel 1020, Steel 1045. Surface treatment: Carburizing, hardening and tempering, nitriding, high ...