... , Cr, Mo, V, S, PFerrous alloy: Fe, Cr, Si, Ni, BNickel alloy: Ni, Cr, Co, Wc, BTungsten alloy: W, Ni, Fe, Cu Products ... and barrel for various models 2. Professional engineers design for you 3. Thousands of drawings can supply for you 4. Insist on developing screw and barrel for ...