I was at my wits end trying to remove a 8mm bolt from a differential. To make matters worse the bolt was counter sunk. I was able to catch the bolt by the remaining shoulder, and after an hour of patience, I removed it and was back in business..Great extractor set.This product worked exactly as describedAs far as I know, this is the highest quality bolt extractor set you can buy. Works like a charm whenever I need them, which admittedly is not that much. Plated to resist corrosion and they come in a nice box too.Worked the first time! The bolt extractors are built really well. Used the 19mm to loosen a rounded oil drain plug.Works like a charm - very rugged - used mine for auto work. Recommend.This bolt extractor set is one of the best tool sets I have and I have a lot of tools . I had a lug nut that froze up on my focus then I stripped it out nobody wanted to mess with it. I got this set, pounded one of the bolt extractor sockets on the lug nut 7/8 box end, jumped on the wrench and the nut came off, didn't even bust the stud. I would suggest this set for anyone that does their own wrenching!!!...