Tool life and cutting forces when machining XC 45 steel

Machinability equations have been developed for prediction of tool life when machining XC 45 steel with P 10 and P 30 carbide inserts. A marked difference in cutability was observed between separate batches of P 10 inserts. A new criterion of tool life is suggested.

Equations are developed relating cutting forces to cutting conditions and to tool wear measurements. It is suggested that the percentage increase of the feed force may be suitable as a monitor of tool performance. The effect of cratering upon feed force is discussed and it is concluded that cratering should not necessarily affect feed force.

A slight positive correlation between cutting force and cutting speed has been observed for the radial and feed forces but not for the vertical cutting force.