An Innovative Machining Strategy for Efficient Peripheral Finishing of Hard Materials with Highly-Varied-Helix End Mill

Grinding is usually applied to the peripheral finishing of hardened steel since the high specific cutting force and low stiffness of slender end mills often causes chatter vibration. On the other hand, varied-helix end mills have suppressed regenerative chatter vibration successfully in the rough machining of flexible workpieces. In this research, varied-helix end mills are applied to the extremely low radial immersion finishing of hardened steel, and the validity of this application is discussed and verified experimentally in terms of suppression of regenerative chatter vibration. A special varied-helix end mill with an extremely large helix angle difference is developed for this new application, and its performance is compared to that of an ordinarily-varied-helix end mill for the low-radial-immersion peripheral finishing of hard materials.