the objective lens which enables variation in the laser focused spot size and therefore the resulting power density a binocular microscope is used to locate the focal plane experiments that were performed verified the decrease of cutting forces breakage into short chips and reduced tool wear during pulse laser assisted machining in performing these cutting tests the laser was operating at an average power output of approximately 125 watts and the laser beam pulse width pulse length was 200 microseconds while the pulse rate was 400 pps the average energy pulse under these conditions is approximately 0 31 joules pulse the resulting peak power per pulse is 1 6 kilowatts and the corresponding power density is 2 u00d7 10 5 watts cm 2 typical energy density per pulse is approximately 40 joules cm 2 these parameters result from a cutting speed of 63 sfpm oxygen was used during certain test runs to increase laser material vaporization the workpiece was bathed in a low flow of oxygen cover gas delivered by tube 40 fig1 and this increased the percent force reduction the use of this and other gases may be beneficial during this treatment an alternative but less desirable two step method involves initially treating the workpiece with a pulse laser followed by machining on a lathe referring to fig6 circumferentially spaced axially extending rows of holes 38 are drilled in the surface of workpiece 39 as it is rotated in the layer of material to be machined by a pulse laser the holes in every row usualy overlap one another subsequently.