Abstract: Tapping small size thread in deep holes in titanium alloy is a very difficult technology in airplane manufacture.The primary problem is that the frictional torque in the flank face of the tap is very big and makes the tap break or rupture,Although we have improved this operation remarkably by vibration tapping technique, with continuously running the vibration tapping pro-cess,the tap teeth are worn gradually and it makes the tap break or rupture also.Therefore,this paper describes some new researches including the study of mechanics model for vibration tap-ping,the analysis ofmechanics characteristic in tap failure,and the method to create an automat-ed monitoring and control system used for vibration control, tap breakage detection and alarm.

Key words: taps, titanium alloy, stress measurement, torsional vibration