... 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 5/8 ... 161.9mm(6 3/8”),165.1mm(6 1/2”)190.5mm(7 1/2”),193.6mm(7 5/8”),200.0mm( ... (8 3/8”),215.9mm(8 1/2”),222.2mm83/4”) 241.3(9 1/2”),244.4(9 5/8”),250 ... /4”)381(15”),393.7(15 1/2”),406.4(16”)444.5(17 1/2”),508(20”),558(22”),609.6 ...