... sleeve bushing 2.ISO9001:2000 Certificated. 3.Oil Impregnate sintered Bushing 4.High precision,durability Company IntroductionYongcheng Group, is a large copper ... , one specializing in the production of various grades of copper products.CertificationWith 27 years’ experience, we value quality and ... 5.Others: aluminum castings, zinc-based alloy sets, copper bushings, sleeve, copper, brass bronze plate