... API 3. Quality products & good service 4. Good feedback of clients Rubber seal/metal seal tricone drill bit : size ... of bearing seal.Main Type Available Size: 6",6 1/2",7 1/2",8 1/2 ... /8",12 1/4",14 3/4",17 1/2", etc. IADC Code:4-- Series, 5-- Series, 6-- Series,etc. 3 ... 5/8:",3 7/8",4",4 1/2",4 5/8",4 3/4",6",6 1/2",7 1/2", ... 1/4",15",15 1/2",17 1/2", etc. IADC Code:5-- Series,6-- Series Rubber seal/ ...