Tools of grade N35/3 and N35/RD25 were tested to .030 in. flankwear at cutting speeds of 500 fpm with 0.010 in/rev feed and 250 fpm. with 0.010 in/rev feed and 0.030 in/rev feed machining EN 9. The results showed that N35/3 gave the better performance at the higher cutting speed and that the two grades gave the same performance at the lower speed. At 250 fpm and 0.010 in/rev feed the wear of both grades was mostly confined to a groove at the depth of cut. With the larger feed both grades of tool suffered severe deformation of the cutting edge.