... benefit, provides the highest quality products and attentive service for our customers". We are looking forward to establishing relationships ... medium,medium-hard drilling information 6) Bit size:8 1/2"IADC code:5372,products details 3,Packingor steel box4 ... 161.9mm(6 3/8”),165.1mm(6 1/2”)190.5mm(7 1/2”),193.6mm(7 5/8”),200.0mm( ... 4”)381(15”),393.7(15 1/2”),406.4(16”)444.5(17 1/2”),508(20”),558(22”),609.6 ...