... installation 3.reduce friction Increased using life mould parts with high quality core holder 1.core holder material:s45c+brass2.has angle ... at guide bearing end,increase of upward resistance. Shenzhen Datong Precision Metal Co., Ltd. is a specialized manufacturer of mold ... , AISI, JIS Standard in China. Established in 2002, Datong Precision had been certified according to ISO9001:2000 and turning into ...