For the price they cut very well. Was able to cut a 1/8" x 1/2" wrench socket into the shank of a 3/4" class 8 hex head screw with no problems. Very clean cut. If you watch your feed and speed and use a good quality cutting oil, they should hold up to minor general machine work.Only 4 stars because these bits are not the inch size listed on the wood holder OR the bit shank.