... .with heat treatment 4.OEM are welcomed casting carbon steel bulldozer gear Quality System CertificateISO 9001Dimension ToleranceCT7Surface RoughnessRa6.4~ ... Treatment, Machine, Polishing, Chrome, Zinc, Nickel PlatingPackingCartons, Wooden Case, Steel Cases, PalletsAdvantage1.More than 20 years experience2.15-20 days ... thermal analysis equipment 5.Passed ISO 9000 Casting Carbon Steel Bulldozer Gear