This paper reports the results of experiments into the reliability and failure of tools in the face-milling of stainless steel. The effect of cutting conditions (cutting speed, feed, depth of cut) on the tool life, as determined by chipping, is investigated. The results show that the chipping distribution is a close approximation to the normal distribution and that the determination of cumulative probability could be determined after 10 iteration tests. From the stand-point of the tool life by chipping, the feed-rate range can be divided into three regions: in the high feed-rate region, the cutting edge of the tool is chipped with built-up edge; in the medium feed-rate region, the cutting edge of the tool is chipped with no built-up edge; whilst in the low feed-rate region chipping rarely occurs. It was observed also that a cutting speed of 85 m min - 1 is optimum for maximum volume of metal removed.