... forward to establishing relationships with you in the near future 1,Structure features:1) Material: 15CrNi4MO2) Rubber/metal sealed bearing3) Jeurnal/rock ... medium,medium-hard drilling information 6) Bit size:8 1/2"IADC code:5372,products details 3,Packingor steel box4 ... ,127mm(5”)130.1mm(5 1/8”),133.3mm(5 1/4”),139.7mm(5 1/2”),142.8mm(5 5/ ... (10 5/8”),295.3(11 5/8”)311.1(12 1/4”),346.0 (13 5/8”),349.2(13 ...