... main products are rock drilling tools and mining tools, including five series, more than 500 types. They are Tapered Drilling Tools ... , Tricone Drilling tools and Coal Mining Tools. Main products:Tapered button bits (28mm, 30mm 32mm, 34mm, 36mm, 40mm, 42mm, 44mm ... ( Hex.32mm, 35mm, 38mm; Round 32mm, 38mm, 45mm, 51mm)Retrac Button bits with different Thread different diameters. (51mm, 64mm,70mm,76mm ...