This set cost six times what the (really bad) Harbor Freight set does. But I'm really pushing various sizes by drilling holes in 304 stainless on my mill. Some of those are half inch holes. Three different setups completed and the drills bits powered through .375 plate superbly well and the cutting edges still look fine. It's a 29 piece set. Comparing to a 115 piece set would set the purchase price up around $240.00. That's up with low-end quality sets from MSC. Took a shot and tried these out. So far, so good.