MAXDRILL drill button bit are available for rock-Soft rock, loose-medium rock, hard rock and any other special formations thread button bitsThread button bits made ... tailored service is waiting for you upon your demand.(1)Thread: R22, R25, R28, R32, R35, R38, T38, T45, T51, ... Conical. (Threaded R32, R38, T38, T45, T51, bit diameter: 45mm-127mm);(2) Main button bits diameters:R32-45mm, R32-51, R32-64 ...