... Timing ChainMaterial: Link Plate, 65Mn; Pin, SUJ2 or SCr440; Bush, 20CrMnMoProcess: ... Pin, carbonitriding treatmentLink Plate Surface Treatment: Bluing, Yellowing, Copper-plated, Zinc-plated, Nickel-plated, Chrome-platedPin and Bush with polishing treatment, and pin with ... accurate grindingHardness: Pin, RC60; Link plate, ...