... Size: 6",6 1/2",7 1/2",8 1/2",9 1/2",9 5/8",9 7/8",12 1/4",17 1/2", etc. IADC ... AvailableSize: 5 7/8",6",6 1/2",7 1/2",7 7/8",8 1/2",9 1/2",9 5/8",9 7/8",12 1/4",14 ... 3/4",17 1/2 ... ",9 7/8",12 1/4",15",15 1/2",17 1/2", etc. IADC Code:5-- Series,6-- Series 17 1/2" tricone drill bit