I bought a set for general use and/or small welders, certainly didn't expect them to be the same as my control square. But damn it was crap. There were ridges and protrusions on both edges of the inner corner relief. Couldn't even insert the part before it was hanging. It's bad enough that I've started grinding it to acceptable accuracy first with a flippin cut-off wheel and then with a diamond lapping wheel. The outside "squareness" was over 0.006" on a 3" long leg lol. For a laugh, I used a belt sander to smooth it out better when they came. It's funny.