Abstract: The over-fixation of the rock bit's tooth hole used to be determined by tests and statistics method in all China's rock bit manufacturers.This method is affected is affected by such factors as processing,testing and so on,and its period is long,and its cost high.For this problem,using the finite element method,we analyzed the over-fixation of the tooth hole of a rock bit,and the distribution laws of stress field aroud the tooth hole.

Key words: tooth hole, rock bit, over-fixation, stress field