... 3.reduce friction Increased using life mould parts with high quality core holder 1.core holder material:s45c+brass2.has ... Square interlock,Tapered interlocks, Taper pin sets . Ejector devices: Two-stage ejector, Accelerated knock-outs,slide core units, Lifter . ... , Guide bush, Angle pin,Shoulder guide bushing, Sprung Cores ,Air poppet valves . Cooling elements: Spiral plug baffles ,Straight plug ...