... Size: 6",6 1/2",7 1/2",8 1/2",9 1/2",9 5/8",9 7 ... seizure resistance of the bearing are improved. 2.Premium O-ring, Optimal seal compression and ... 6",6 1/2",7 1/2",7 7/8",8 1/2",9 1/2",9 5/8 ... minimum.Main Type AvailableSize: 8 1/2",9 1/2",9 5/8",9 7/8",10 ... 2",7 1/2",8 1/2",9 1/2",9 5/8",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 ...