This looked like a very good set at about half the price of a Milwaukee drill and tap. I thought I'd try them out and see if they hold up. I used two different jets 10/32 and 10/24, pre-drilled 1/8" holes and used faucet oil on both. It broke on the second try, and the second also broke in just a few tries. I went with the Milwaukee brand and used the same process with no problems: same drill, same RPM, same oil, same pre-drilled hole. Milwaukee brand could drill through with no problem. Well, I'm guessing it's cheap steel or poor workmanship, but it's not even worth it for half the price Price.