Abstract: Turning tools tipped with rotating CBN inserts were designed and tested. The inserts with diameters of 9.5, 12. 7, 23 mm were accommodated by different collets and the tool holders were able to provide adjustable rake angle and inclination angle. The spindle of the tools was supported with either plain bearings or ball bearings. The investigation demonstrated that the surface quality of the machined parts was dominated by surface waviness which could be reduced by using appropriate cutting speed, feed rate and tool geometry. With ball bearing holders having 12. 7 dia. inserts, optimum cutting conditions in terms of lowest waviness were found via numerical optimization based on the experimental data. Better machining quality could also result from tools using smaller cutting inserts and with smaller bearing clearance. The experiment also showed that the tool holders with plain bearings were more likely to generate lower waviness.

Key words: cubic bor on nitr ide cut ting t ools, cutting tests, holder s, rotar y cutting, waviness