... 2,We are outstanding because of being professional. We got the Certificate of ISO9001 in 1999 Tapered Button bits, Retrac Button ... 45mm ,51mm,57mm,64mm,70mm,76mm, 89mm, 102mm ,115mm,127mm and so different degree Thread for example: R22, R25, R28, R32 ... 115mm, 127mm.)Down the hole drilling(drill bits, hammers, spare parts, drill tubes)Buttons type :Spherical, Ballistic retrac and drop center button bits