... rate and added cutting structure durability in medium-to-medium hard formations .The HSN rubber O-ring ... oil well drilling2,Model: various kinds and according to the requirements of customers3,Material: ally steel, tungsten ... ,65mm,76mm,93mm,95mm,98mm(3 7/8”),101.6mm,114mm,118mm,120mm,127mm(5”)130.1mm( ... 737512,522,532,612,622,632,7326. How to ship the bits to your country? You Satisfaction Is Our Purpose ...