On Sun, 23 Nov 2014 22:31:21 -0600, -MIKE- wrote:

A brand new square should be square.
I know how to check and adjust squares.
I do it when I drop one... not when I buy one. :-)

There's a tolerance on all squares. Greatest for a rafter square,
middling for a combination square, and minimal for an engineering square.

And an engineers square is square on both outside and inside.