After more than 200 holes, the drill still cuts easily. The holes are very clean and free of burrs. Just use a slow speed and lots of cutting lube My two complaints are: 1) The description here says the bits will cut through material 1/2" thick. The actual product packaging says the bits are good to a depth of 1/4". .The bottom of the bits is 1/4". This became a problem for be because I was drilling 5/16" thick stock and had to drill a pilot hole and drill it through the back of the board. The time it took to drill these holes easily quadrupled. and it came out a lot less clean than the holes I drilled in the 3/16" plate. 2) The pilot drill will wander if not using a significant center punch. After making a jig and trying, without using a center punch to save time realized this was a bad idea, in hindsight maybe if you removed the pilot bit it would work.