... .more than 20 years experience casting rigid torque arm for trailer Quality System CertificateISO 9001Dimension ToleranceCT7Surface RoughnessRa6.4~ ... Analysis, Tensile Test, Dimension Inspection, Hardness TestingSurface TreatmentHeat Treatment, Machine, Polishing, Chrome, Zinc, Nickel PlatingPackingCartons, Wooden Case, Steel ... CASTING FACTORY & EQUIPMENTS: casting rigid torque arm for trailer