... , DIN, GB, BS, JIS, NF, AAR Investment Casting of Suspension Parts for Trailers 1.Quality system certificate: ISO 90002. Standard ... Ductile Iron, Aluminum, ect . 10. Surface Treatment: Heat Treatment, Machine, Polishing, Chrome, Zinc, Nickel Plating 11.These parts are used ... in machine assembly, valve &pump parts, auto &motorcycle parts, train & ...