SpecificationFront sprocket 13T,14T,15T,16T,17T etcRear sprocket 35T,36T,37T,38T,39T,40T,41T,42T,43T,44T,45T,46T,47T,48T etcChain 415,420,428,520 etcMaterial45# steel(SAE 1045), A3# steel(SAE Q235), 16Mn steel etc.Heat treatmentHigh frequncy quenching,carburizationSurface treatmentsand blasting ,dull polish, galvanization ,chrome..