... & steel teeth tricone bits 2. ISO & API 3. Quality products & good service 4. Good feedback of clients IADC 517 537 8 1 ... ",9 7/8",12 1/4",17 1/2", etc. IADC Code:4-- Series, 5-- Series, 6-- Series,etc. 2. Elastomer ... ",12 1/4",14 3/4",17 1/2", etc. IADC Code:4-- Series, 5-- Series, 6-- Series,etc. 3. Air ... ",9 7/8",10 5/8",12 1/4", etc. IADC Code:5-- Series,6-- Series,7-- 4,Non-Sealed Roller ...