... ,118mm,120mm,127mm(5”)130.1mm(5 1/8”),133.3mm(5 1/4”),139.7mm(5 1/2”),142.8mm(5 5/8 ... 7/8”)152.4mm(6”),155.5mm(6 1/8”),158.7mm(6 1/4”),161.9mm(6 3/8”),165.1mm(6 ... .8(10 5/8”),295.3(11 5/8”)311.1(12 1/4”),346.0 (13 5/8”),349.2(13 3 ... production technology ensuring the quality satisfy international request. API 12 1/4" IADC127 steel tooth tricone bit /rock bit with high quality ...