... Answer : Yes. All our activities are certificated by ISO and API, we have many regular customers in many countries and regions ... 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”),346.0mm (13 5/8”),349 ... ,637,737512,522,532,612,622,632,7323 cone rotary rock bit 4 5/8"IADC537G