28B B Series Roller Chain 1.material:40MN/A3 2.pitch ... .5/6.0mm 4.surface treatment:heat treatment 28B B Series Roller Chain1.material:40MN/A32.Standard Chain3.color: ... 428H, 520, 520H, 530, 530H, 05MA, 05MB, 05MC, 06MC 2. O-Ring Motorcycle chains: 428SO,520SO,525SO,530SO3. Roller chains: A ... series and B series4. Silent chains: SC3,SC4,SC5,SC6,SC8,SC105. ...