... 3. Quality products & good service 4. Good feedback of clients Rubber seal/metal seal tricone drill bit : size from 60mm to ... 7/8",12 1/4",17 1/2", etc. IADC Code:4-- Series, 5-- Series, 6-- Series,etc. 2. Elastomer ... 1/4",14 3/4",17 1/2", etc. IADC Code:4-- Series, 5-- Series, 6-- Series,etc. 3. Air ... 4",15",15 1/2",17 1/2", etc. IADC Code:5-- Series,6-- Series Rubber seal/metal seal tricone drill bit