1. best drill bits for quarrying, mining, construction 2. button bit, thread bit, dth bit, etc 3. export to over 40 countrie KAIYU, as a professional factory producing drill bits, we have more than 30 years produce and design experience. By now, we have exported to more than 40 countries, like US, Australia, Brazil, Norway and Saudi Arabia, etc.We have many kinds of drill bits for our customers ...