... or ISO 9001 2-Bit size 6"-17 1/2" 3-Bit high quality and low ... establishing relationships with you in the near future 1,Structure features:1) Material: 15CrNi4MO2) Rubber/metal sealed bearing3) ... -hard drilling information 6) Bit size:8 1/2"IADC code:5372,products details 3,Packingor ... 5/8”),295.3(11 5/8”)311.1(12 1/4”),346.0 (13 5/8”),349 ... 381(15”),393.7(15 1/2”),406.4(16”)444.5(17 1/2”),508(20”),558(22 ...