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