... .ISO 9001 4.more than 20 years experience casting steel parts of trailer top plate Quality System CertificateISO 9001Dimension ToleranceCT7Surface RoughnessRa6.4 ... Composition Analysis, Tensile Test, Dimension Inspection, Hardness TestingSurface TreatmentHeat Treatment, Machine, Polishing, Chrome, Zinc, Nickel PlatingPackingCartons, Wooden Case, Steel Cases, PalletsAdvantage1 ...