Review on GOTICAL 5/8-24 Black Steel 308 Jam Nut - High-Quality 7.62, 300 (5 Pieces) by Michael Gilmartin

All 5 were difficult to wind on the running threads. 2 out of 3 were cut crooked so they didn't screw in flush with the shoulder, so they're useless if you're going to use them to time something (like a muzzle device). They have to be 100% concentric and flush, and of the three "good ones," I wasn't sure about any. Of course, given that they were made in China, you should take that into account. I'd happily pay double the price if they were made in the USA and they were all concentric and perfectly square and flush cut. I really hate giving things bad grades, but that's the way it is.