Starrett Steel Combination Square with Square Head - 12" Blade Length, Cast Iron Heads, Reversible Lock Bolt, Scriber, Spirit Level, 4R Graduation Type - 11H-12-4R

Starrett's 6" inch combination square is regarded by many as a the best on the market. I haven't evaluated any of the other high end squares, but to my mind it is nearly flawless. Why do I think this? It is square, not kinda' sorta' square if you hold it right. I mean square to the point where you can't detect any light between a machinist's reference block and the body or blade even with strong backlighting. Your eye can see light from a 0.001" opening so you know the square is at least this square. You can tighten the thumbwheel using only one hand to achieve the squareness described above. The numbers and lines are engraved so they don't wear off. The engravings are deep enough so that you can put the points of your dividers in them to accurately set the distance between the points. The satin finish on the blade makes it easy to read. The "4R" marking system (1/8, 1/16, 1/32 and 1/64) is more useful than you might realize. It cuts down errors due to misreading the scale and is faster. Reinserting the blade after removing it from the body is easy. On some squares, this is a major hassle. On the Starrett, the protrusion in the body which holds the blade generally stays in place when you remove the blade. If it gets misaligned with the slot, it is easy to rotate it back to parallel with the body so you can reinsert the blade. The spring holding the protrusion has the proper amount of stiffness. Another good thing is that it is rugged. I haven't hit it with a hammer or put a torch to it, but it has suffered a lot of drops onto a wooden floor without damage. Why don't I think it is perfect? It will rust (like almost all steel) if you don't take care of it. By taking care of it I mean storing it dry, free of salt from sweat, and dust. Not a big deal, but this is a precision square so treat it with the care it deserves. A wise man once said, "When you buy quality, you only cry once." Do yourself a favor and buy this square.

Nice high quality very accurate not super heavy but definitely not lightweight they slide nice and easy and it tightens down good to keep it in place easy to read very high quality Steel wouldn't buy anything else

Best square for a trim carpenter and do a mill worker, the fit is great, dead square out of the box, and holds it measurement where u put it. As it should. Yes it is expensive but so is using a cheep knock off and getting bad cuts

Classically trained engineer here who has rekindled woodworking as a hobby. I haven’t touched woodworking since high school but I have so many hobbies that require accuracy, I have learned a long time ago that quality tools matter. After some research into brands, Starrett came up all the time as being among “the best” for long term accuracy and craftsmanship. Starrett did not disappoint, when checking for square it was absolutely dead on accurate against every one of my expensive calibrated machinist levels and squares. The 45 degree was also dead on. I bought the forged steel 12” 4R model. It’s nice and heavy. I gave it a light coat of oil that I use to keep my firearms free from rust until a few days before I know I am going to use it, at which point I take off all the oil and apply a thin coat of shop wax to it so I don’t get oil on my project. Some people just use shop wax and call it good. Which I’m sure is fine. I’m weird about rust I want to avoid it at all costs. I live in one of the most humid states so all my tools and firearms get some TLC at least twice a year. Are there less expensive and just as accurate alternatives to this product? Of course! But the reputation (whether it’s a confirmation bias or not is up to you to judge) has been earned by others and myself. Buy once cry once. Or you get what you pay for. Pick your adage. 5 stars in my book!

This is one of those unique tools that lives in a special place in my cabinet. It reminds me of a different world where craftsmanship and engineering reign supreme. Why the superlatives? Because it is more than a very well made, very accurate, high-quality combination square: It is because when I take this tool in my hands, I FEEL (add emphasis) different, and I work differently because of it. Corny, you say? It's just a pricey combination square, you say? Perhaps. But for me, there are only a handful of tools in my collection that evoke an emotional response whereby their very use transports me back to my grandfather's shop, where I can feel the textures, hear the machinery, and smell the varnish, dust, motor oil and age. This is one of those tools. It makes me nostalgic for an age- real or imagined- before outsourcing and cheap tools, when quality was the norm. This combi square simply looks and feels different than many of my other layout tools, aside from being more accurate and precise than any of them. It looks... machined. Enough of waxing emotional. this is a high quality, precision tool that belongs in your tool box if you need that kind of precision (squaring-up your miter saw or table saw, for example) and can afford it. I notice that this is now going for thirty bucks more than when I bought it two years ago. Yikes. Is it thirty bucks better? I doubt it. But then, I'm devoting five stars to this tool in part because of how the quality makes me feel, not just whether it is worth the dough for something that is very, very square and well-made. Would I recommend this tool for someone just to use for framing houses or building chicken coops? No, I wouldn't, as there'd be less bang for the buck there versus other combi squares that are square enough and go for far, far less. I would wholeheartedly recommend this, however, for those who need a precise layout instrument that will last, that has smooth, well-engineered action, and is dead level, square, and straight... And that makes you feel good just by holding it.

He’s anxious to use it on his projects and immediately felt the difference in weight and quality, from a lesser brand he has been using.

This thing is so nice, it’s very accurate and the steel it’s ground out of is incredible hard. It barely has any scratches on it after a few months in the metal shop

I purchased the Starrett C33H-12-4Ry combination square ($113) together with an Empire Level E250 ($15.94) for comparison. As far as I can tell, both are perfectly square. Both are made in the USA, but the Starrett does have a heftier, sturdier feel and appearance. (It weighs a bit more: 13.875 oz. vs 11.5oz) The Starrett’s bubble vial only has a tiny little window, which makes it rather difficult to “read”. In contrast, the Empire E250’s bubble vial is fully exposed and viewable from any angle, although this does makes it more vulnerable to potential damage. The Starrett’s ruler is significantly easier to read than the Empire. Both rulers have etched markings, but the Starrett’s are much deeper and darker. The matte finish of the Starrett ruler also serves to improve readability. I wouldn’t say the E250’s ruler has a glossy finish, but it is noticeably shinier and can cast a glare from reflected light in the shop. Both models have a spring-loaded thumbscrew which makes reversing the rulers a breeze. Both rulers are the same length and width, but the Starrett’s is slightly thicker. When it comes to measurements, the Starrett wins hands down. The 1/8”, 1/6”, 1/32”, 1/64” increments, with “quick read” markings for the 32nds and 64ths (i.e., every 4th increment is marked with a number) make it almost too easy to read. In contrast, the Empire E250 has 1/8” and 1/16” on one side and 1/16” and 1/32” on the other side, and has no numerical markings on either side for anything smaller than an inch. When lined up side by side, the markings for both rulers matched perfectly, but my E250’s 8 1/8” marking is partially missing, and unfortunately it’s the part at the ruler’s edge. Starrett definitely wins the quality control battle. All in all, I am very satisfied with both products, and I can see both lasting several lifetimes, but I find it very difficult to justify the extreme price difference of the Starrett. Sure, it is better quality and has better markings, but in my opinion, that does not justify the nearly $100 price increase over the Empire square.