... tempering Heat treatment, surface hardening Dear customers, motorcycle roller chain 520 is for motorcycle TRANSMISSION SYSTEM.Roller chain Quality is vital for riding safety. As ... which is strict quality test result. 1.Motorcycle Roller Chains:25H (04CH), 415, 415H, 420, 420H, 428, 428H, 520, 520H, 530, 530H ... A5,A66. O-ring chains and xw-chains: 420,428,520,525,530,630 (Racing Chains)7. Leaf chains: ...