MAXDRILL drill button bit are available for rock-Soft rock, loose-medium rock, hard rock and any other special formations thread button bits Thread button bits made with ... good price .No matter what kinds of rock-Soft rock, loose-medium rock, hard rock and any other special formations, just ... T38, T45, T51, bit diameter: 45mm-127mm); (2) Main button bits diameters:R32-45mm, R32-51, R32-64, R32-76,T38 ...