First thing I checked right out of the box for squareness. Both are at least 1 degree off, if not more. I have a few squares that I use and I check them regularly to make sure they are all correct as things can get a bit out of hand with frequent use. I compared this set of squares to a frame square, a carpenter's square, a polygon square, and a fine furniture marker square. All of them are known to be good for me, and all showed slight gaps when used against this set. Both the inside and outside corners are offset by the same amount. I can try to put them in my vise and line them up, but that should never be something you should do with a new set of squares - EVER. If that doesn't work, they end up straight in the trash. I will contact the company and let them know if I have a bad batch. But a question arises. How did they pass their quality control team? I mean they are designed to be square and they are not!