Very good performance three cone rotary bit, high downhole speed and long working life 9 7/8" IADC537G is a regular types, we ... by ISO and API, we have many regular customers in many countries and regions who are trading or drilling contractors. We have ... /8”),250.8mm(9 7/8”)269.8mm(10 5/8”),295.3mm(11 5/8”)311.1mm(12 1/4”),346.0mm (13 ... 637,737512,522,532,612,622,632,7323 cone rotary bit 4 5/8"IADC537G