... supplier specializing in various castings (cast iron) of pulleys & sheaves as per customers' drawings & samples. FEATURES TO Cast Iron,CASTINGS OF PULLEYS & SHEAVES. 1 ... .Material & Standard:grey iron(GG20,GG25,GG30),ductile iron(GGG40,GGG50);JIS,DIN ... ,big ring gear,bolster,frame,rear frame,front frame,engine block.