The tri-cone roller-cone bit comes in which two configurations?

• A. Milled tooth and tungsten carbide tip
• B. Milled tooth and carbide insert
• C. Carbide insert and diamond insert
• D. Diamond insert and steel teeth

Answer: (B)

Tri-cone bit tooth construction comes in two main forms. The first is milled tooth, where the teeth are formed by milling directly from the steel body, giving a sturdy, self-sharpening edge. The second is carbide insert teeth, where hard tungsten carbide inserts are brazed into the teeth area to provide superior wear resistance in hard, abrasive formations. Diamond inserts aren’t used on roller-cone bits, so a configuration with diamond inserts isn’t applicable here. So the two configurations described are milled tooth and carbide insert.