... rock, hard rock and any other special formations thread button bits Thread button bits made with high quality of best quality alloy steel bar ... , R38, T38, T45, T51, bit diameter: 45mm-127mm); (2) Main button bits diameters:R32-45mm, R32-51, R32-64, R32-76,T38 ... -89mm, T45-102mm,T51-89mm, T51-102mm, T51-127 etc.(3)Package: in wooden case or in carton or as client ...