Hello. Haven't used them yet but they look good. Carbide from a manufacturer who knows carbide is what it is. Just don't pull the silly move I made and order a size that looks like what it looked like in the photos, check the specs. Most of it isn't half an inch across, and how often is the average person going to poke a tiny hole in the concrete? Also this case; while the really hard and beautiful was clearly not made for these parts. that's extra. Sir, you can put them in, but they'll rattle, and then you'll have room to figure out what you put in there. After that you want it to be transparent. But hey, it sure is a good thing.