1. specialling in spur gear producing 2, material : brass , stainless steel POM ... alloy, bronze, brass. Surface treatment: Carburizing, hardening and tempering, Nitriding, high frequency treatment, black of oxidation, zincing, nickelage. Machine: ... engine lathe, milling machine, drilling machine, hobbing machine, grinder, gear shaper, testing center. Competitive price & prime quality & best service ...