... hard rock and any other special formations thread button bitsThread button bits made with high quality of best quality ... T38, T45, T51, ST58, T60Button bit face design: Flat face, drop centre, Normal and Retrac body.Tungsten carbide (Buttons ... , T45, T51, bit diameter: 45mm-127mm);(2) Main button bits diameters:R32-45mm, R32-51, R32-64, R32- ... .(4)Productivity: 10000pcs/ month MAXDRILL drill button bits