Abstract: This paper introduces the experimental research on raising rotating speed of cone bit. The experimental results and practice have shown that by boronizing the journal bearing of cone bit and by using suitable solid lubricant and seal, and reasonable process technology, the rotating speed of cone bit can be raised from 60 to 120 revolutions per minute. As a result, a good drilling effect has been obtained and drilling cost has greatly been reduced

Key words: Cone bit Journal bearing Process technology Bo