28B B Series Roller Chain 1.material:40MN/A3 2. ... .5/6.0mm 4.surface treatment:heat treatment 28B B Series Roller Chain1.material:40MN/A32.Standard Chain3.color: ... : 428SO,520SO,525SO,530SO3. Roller chains: A series and B series4. Silent chains: SC3,SC4,SC5,SC6,SC8,SC105. ... LH series8. Double pitch conveyor chains with attachments: 2040,2050,2060,20809. Nickel-plated chains: 25NP,35NP,41NP,40NP,50NP10 ...