... service 4. Good feedback of clients 17 1/2" tricone drill bit : size from 60mm to 26 inch,metal sealed ... /2",9 1/2",9 5/8",9 7/8",12 1/4",17 1/2", etc. IADC Code:4-- ... /2",9 1/2",9 5/8",9 7/8",12 1/4",14 3/4",17 1/2", etc. ... /2",9 5/8",9 7/8",10 5/8",12 1/4", etc. IADC Code:5-- Series,6-- Series ... 2",9 1/2",9 5/8",9 7/8",12 1/4",15",15 1/2",17 1/2", ... IADC Code:5-- Series,6-- Series 17 1/2" tricone drill bit