... holding capability and bearing life.Sealed Bearing Structure 1.Abrasion resistance and seizure resistance of the ... Type Available Size: 6",6 1/2",7 1/2",8 1/2",9 1/2",9 5/8",9 ... /8",6",6 1/2",7 1/2",7 7/8",8 1/2",9 1/2",9 5/8 ... dropping to minimum.Main Type AvailableSize: 8 1/2",9 1/2",9 5/8",9 7/8 ... 4 3/4",6",6 1/2",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-- ...