... in drill bit manufacture API&ISO9001 certification API12 1/4" Kingdream IADC127 Roller Steel Tooth Bits As the professional supplier of rock ... cone bits,multicone bits,steel tooth bits,insert tooth bits,roller bits,drill bits,drilling tools,etc.Steel tooth tricone bitsFor ... and heel row. 0.35~1.05120~50 API12 1/4" Kingdream IADC127 Roller Steel Tooth Bits