First of all – let me say I’ve heard all the argument before, And I agree “only square is square” So don’t mount your high horse on me.
I have seen articles that date many years ago of the importance of maintaining a good square. Well I just seen another, and frankly I am just a teensy bit put off about it. The current issue of Woodcraft magazine is where you can read this article. It may appear to you that this guy works for Starret, or possibly for Woodcraft. Furthermore it may appear that he is selling Starret square’s, you can make your own judgement about that.
I say that while there are squares that are not perfectly square, the ones that are not square are off less than .250 degrees. That amount (especially in my old age-and with my eye) are not noticeably detected until you get to about 20” from the focal point. The cost of some of these squares can reach a hundred $ mark. My squares like the framing square, combination square, speed square, and engineers square, were all purchased from my local hardware store, these are the ones that are being warned against. So I took to my shop and put these squares to the test. I first sharpened a #2 pencil to a very fine point, and fixed a 24” x 24” sheet of poster board to a table and began marking out a square then a second square, on the first I drew a line with my framing square and checked it by flipping and redrawing a second line in 24” it was dead on, wow I never expected that!! I then preformed the same test on my other squares and the results of all were the same as the first. On the second I drew out squares on top of each other with all my squares—sharpening my pencil as needed. The results of that test were within 1/2 of the thickness of a very sharp pencil. Possibly an error on my part. which in the end I conclude that for at least the squares that I brought home were in fact square. Now I know that this test of mine is not scientifically sound, but give me a break who are these annal people that want me to go out and buy a square that cost six times more than mine simply because it says Starrett on the face. Oh yeah did I mention that I have a Starrett and I used it to measure the square on other squares they were square. I’m square—You square???
-- Lizardhead---Yeah but it's a dry heat--Tempe, Az