1 high grade screw barrel assembly parts 2 Applying ISO9000 management system screw barrel assembly partsScrew Assembly PartsDistributor, Collar, Screw Cap, Washer & Screw ElementsBarrel Assembly PartsEnd cap, Flange, Adaptor, Cooling Ring, Nozzle Technological Processblanking-quenching and tempering-rough machining-semi finish machining-finish machining-nitrating treatment or bimetallica ...