... Treatment: Phosphated, Nitrided,Chrome plated 3.ISO9002, QS9000, TS16949 engine piston ring set OEM manufacturer 1.Dia from 90mm---139mm2.Engine Type: W04D ... Co., Ltd. DWIT History: more than 45 years. DWIT products:Piston ring, piston, engine bearing, cylinder liner, liner kit, engine valve, valve ... according to samples or drawings. Desire our cooperation. engine piston ring set OEM manufacturer