Common Roller Cone Bit Dull Characteristics Causes
Some of the dull characteristics listed In Our Bit Dull Grading Guide are self-explanatory. More detailed description of the two-letter codes can be obtained from bit companies. Examples of some of the dull characteristics for Roller Cone Bit Design are shown below.

BROKEN CONE (BC) - Roller Cone Bit Dull Characteristics

The broken cone in this photo was caused by hydrogen sulfide embrittlement. A cone also may break when the bit hits a ledge during a trip (check
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