Abstract
This study describes the effect of axial depth of cut upon a tool life in endmilling of hardened steel. The cutting force usually fluctuates in endmilling, but the fluctuating cutting force can be held down under adequate cutting conditions. Its condition is theoretically determined with the axial depth of cut, the number of flute and helix angle of end-mill.
In this paper, it is made clear that the restraint of fluctuating cutting force makes the tool life to be longer, and that the actual relief angle is an important factor for tool life, namely the actual relief angle is altered by the fluctuation of cutting force. As a result, the lower relief angle causes a longer flank wear and a higher flank temperature the flank wear become maximum in the spot where the relief angle is small.
