I just got this Irwin square today, and at this price point im very pleased. Nice heavy build quality along with touches like a brass lock nut, brass knobbed scribe that is firmly held in the casting by a friction sleeve and even a brass level plug really add to the build quality and heavy duty feel of the casting which is itself nicely done and doesn't look cheap -- I also have a comparable Stanley and I like this one better, the casting is heavier and thicker at the machined edges like a Starrett and feels like a bit better quality than the Stanley. The Irwins rule is nice and thick, easy to read and made of stainless steel not clear coated metal that will peel and rust as my Stanley has, but I have no use for the mm scale on the Irwin, I think they should make either one or the other and not force metric on you if you don't need it -- I don't know a single carpenter at least here in the US that works with mm. The casting borders are nice and thick on the machined sides, giving the look of maybe a Starrett or similar - However a Starrett is around $100+ and the casting on it is iron, which isn't as soft as the Irwins aluminum or zinc whatever it is - but the Irwins cost is MUCH lower and Starrett quality is legendary & in a different class - but you pay dearly for it and most of us cant afford that kind of luxury for it to be lost or stolen on a job sight. I checked my example for squareness soon as I got it as I saw a reviewer who said his was not, fortunately mine is right on so buyers should always check, indeed any tool that involves accuracy should be checked and verified. I did spend some time gently cleaning up the casting and rules corners and edges with a stone, lightly oiled the threads and moving parts and now it slides much smoother than when I first got it - it wasn't bad mind you just needed a bit of "optimizing" to make it good as it could be - Im very pleased and also glad I bought the 12" version as well elsewhere, what ive said in this review also applies to the 12" version and im very pleased with both examples. Empire makes one of similar quality and a stated accuracy within .002 of an inch and price is comparable but the Irwin wins out with a bit more brass bling, for example the level plug is plastic on the empire and brass on the Irwin, and the blue Irwin casting is an eye catcher if that's of any value. Oddly the Irwin makes no specific claims regarding accuracy on their packaging, but they should as it seems to exude enough quality to back it, at least my example does. Im even tempted to purchase the 16" version as these are such a good value. If I had any criticisms, it would be to be careful about dinging the softer aluminum casting on the machined corners,as this would cause out of square measurements, but it is a precision measuring tool and should be treated as such, but thats not always reality on a job site, and no square in this price range im aware of has an iron casting so im not saying the Irwin is at fault since all castings in this price ranges are made of similar material just stating fact, aluminum would be easier to ding than iron, but price is related to material cost so I still say for the price this square is a bargain and I don't see how you could find one any better for the price. Final word, there are many very good reviews for this square and that speaks for itself, you cant go wrong for the money its a really nice tool.