ISO standard Material:45# steel.A3 steel,16# Mn Specification:415,420,428, ... ,520 FOB price:USD0.3-5.0 Motorcycle sprockets 1) Material:45# steel,16 # Mn,A3 steel2) Specification:415,420,428 ... easily! Our main srockets types,or send us your drawing! Standard sprocket--Valen