The first thing I noticed upon unpacking was a large burr on one of the holes. It's okay, but it's a sign of poor quality and minimal quality control. I put everything together and it looked solid enough to fit my SDS drill easily, but I did notice that the pilot drill was slightly off-center. Again, I wasn't too concerned. I used it to get through a brick. I didn't expect perfection. I used it to drill through a brick for some plumbing. When drilling, the set screw loosened and the pilot drill fell out as I pulled out the hole saw. I thought maybe I didn't tighten it enough the first time, so I went and got an adjustable wrench to tighten everything back up. Like mine, the head of the set screw broke while tightening. I was able to finish my work but I will never be able to disassemble this screw. For quality reasons, I can only recommend this hole saw if you are looking for a disposable tool.