Carefully choose raw material suppliers in accord with Supplier Approval Procedure, purchase the domestic top raw material according to incoming Inspection Procedure, so ZKBM ensure consistency of bearings.All raw materials conform to national industry standards. Bearing materials are mainly high purity moulded steel, which can improve service life of bearings, ensure high reliability and reduce unexpected downtime for users. In order to ensure quality of raw materials and outsourced parts used in the manufacturing of high-quality bearing products, we have formulated strict incoming Inspection Procedure, which contains inspections of chemical compositions, high-amplified and low-amplified metallographic structure of raw materials ,physic-chemical analysis of outsourced parts.