I am looking for a good 6" try or combination square that is actually square. Are the try squares better or more accurate than combination? I was looking at the 6" woodpecker try square. Does anyone have any info on these? What about machinest squares accuracy? I bought a crown 6" from woodcraft($25.00) but it is not square. So I am looking to spend more to get a good one that I can trust. Recomendations please.