... rotary bit, high downhole speed and long working life 9 7/8" IADC537G is a regular types, we found it ... 7 1/2”),193.6mm(7 5/8”),200.0mm(7 7/8”)215.9mm(8 1/2”),222.2mm(8 3/4”) 241.3mm(9 ... 1/2”),244.4mm(9 ... 5/8”),250.8mm(9 7/8”)269.8mm(10 ... 5/8”),295.3mm(11 5/8”)311.1mm(12 1/4”),346. ...