Impact assessment of ultrasonic vibrations on the stress state of the hole surface layer when treated by the calibration method

A design project for calibrating holes in parts, e.g. in hobs, discs, gear wheels, un-der conditions of ultrasonic effects application is suggested. Formula, providing a way for varying the value of the ultrasonic pulse pbr in a part is derived. It allows ensuring the required accuracy of the hole at lower pressures in the contact zone of a mandrel with the treated surface and, as a consequence, to reduce the magnitude of the traction force of the calibration process, which is especially important in hole-making operations for parts subjected to heat treatment.