... bub Japan 1. Japan standard 2. A B C Single Double type 3. 45 steel \ A3 Q235 A-typeA-type sprockets (plate wheel) have ... .80C, 100C, 120C, 140C, 160C, 180C, 200C, 240C.Duplex B-typeDuplex C-typeThese sprockets(duplex) with one side or both hubs may ... , 2060B, 2062B, 2080B, 2082B, SUS2040B, SUS2042B, SUS2050B, SUS2052B, SUS2060B, SUS2062B. A B C singgle double Sprocket welding in Japan