... rock, hard rock and any other special formations thread button bitsThread button bits made with high quality of best quality alloy steel bar ... waiting for you upon your demand.(1)Thread: R22, R25, R28, R32, R35, R38, T38, T45, T51, ST58, T60Button bit face design ... , ballistic and Conical. (Threaded R32, R38, T38, T45, T51, bit diameter: 45mm-127mm);(2) Main button bits diameters:R32-45mm, R32-51, R32 ...