... years experience in well drilling equipments 1 Specification:Size9 7/8”(250.8mm)IADC632GBearing TypeAir cooling roller bearing bitThread Connection6 ... Available sizes:60mm,65mm,76mm,93mm,95mm,98mm(3 7/8”),101.6mm,114mm,118mm,120mm,127mm(5”)130.1mm( ... 2”)190.5mm(7 1/2”),193.6mm(7 5/8”),200.0mm(7 7/8”)212.7mm(8 3/8”),215.9mm(8 1/2”),222 ... ”),244.4(9 5/8”),250.8(9 7/8”)269.8(10 5/8”),295.3(11 5/8”)311.1(12 1/ ...