... box, steel box or as your requirements Model 6-17 1/2(inch)Type tricone bits,steel tooth bits, PDC bitsApplicable water ... very soft poorly compacted shales ,sandstone, clays, salts and soft li mestones. Size and IADC available: 3 3/4" to 26 ... ”),161.9mm(6 3/8”),165.1mm(6 1/2”)190.5mm(7 1/2”),193.6mm(7 5/8”),200.0mm(7 7 ... 3/4”)381(15”),393.7(15 1/2”),406.4(16”)444.5(17 1/2”),508(20”),558(22”),609.6(24 ...