... for quarrying, mining, construction 2. button bit, thread bit, dth bit, etc 3. export to over 40 ... bits, we have more than 30 years produce and design experience. By now, we have exported to ... 40 countries, like US, Australia, Brazil, Norway and Saudi Arabia, etc.We have many kinds of ... bit, taper chisel bit and taper cross bit), thread bit( R thread and T thread), retrac bit and dth bit( from 3" ...