... to your request best service hot sale drill bitsThread button bits1. Rope thread:R25 R28 R32, R33, ... , T45, T51, ST58, T60 GT 60.2. Main button bits diameters: R32-45MM, R32-51, R32-64, R32-76 ... 7°, 9°,11°, 12°.2. Type: flat bit, cross bit, button bit3. Main bit diameter: 30mm, 32mm, 36mm, 40mm ... Package: in wooden case or in carton.Tapered button bits are mainly used in mining,coaling,metaling and etc ...