... 5)Tungsten carbide/Wolfram carbide Double-alloy levelLevel A - containing Tungsten of 40%Level B - containing tungsten of 25%Level C - containing tungsten of ... InspectionAs the screw and barrel are the important parts for plastic extruders and injection molding machine,they affect the ... of extruder screw barrel and injection molding screw barrel for Haitian,Demag,Engle,Nigrobossi,KMD,NPM,BOY,HUSKY, ...