... main products are rock drilling tools and mining tools, including five series, more than 500 types. They are Tapered Drilling ... Hex.32mm, 35mm, 38mm; Round 32mm, 38mm, 45mm, 51mm)Retrac Button bits with different Thread different diameters. (51mm, 64mm,70mm,76mm ... the hole drilling(drill bits, hammers, spare parts, drill tubes)Buttons type :Spherical, BallisticWe have our own special steel factory, we ...