# combination square isn't square



## GISer3546 (Jan 30, 2013)

I have a cheapo big box store 12" combination square. After trying to use it for weeks I learned how to check its squareness.... its nowhere close (as much as 1/8th inch off at the 12" mark). I have been looking into the higher quality alternatives and could use some help. I've looked into starrett but am wondering if the $100 cost is worth it compared to a $60 pinnacle or a $30 wood river square.


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## Tilaran (Dec 22, 2012)

Can you get Truper or Urra tools up there ? Good metal, well marked, heavy steel, and under $25.Both brands remind me of old school Craftsman tools. Real decent/good prices. Viva Mejico hermano ! Calidad !


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## ryan50hrl (Jun 30, 2012)

You might check out the new empire squares guaranteed square to .001. I bought one for 15 or so and it's dead on....


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## BWSmith (Aug 24, 2010)

How square do you want it?

Starrett's are nice,we're a Brown & Sharpe shop,both are top drawer.Older Craftsman machinist squares are nice,as are Lufkins.These last two are available reasonably on the used market.I'd pay 20$ for a nice older Craftsman/Lufkin.

If shopping new,in a store.....take a "known" good,framing sq with you.Hold them up to a lite source....if you can't find one that satisfies,leave and find another store.


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## amckenzie4 (Apr 29, 2010)

I picked up a 16" Empire square at Home Depot a few years ago, and it's perfectly square if I tighten it down all the way. It was cheap, too... I'd try buying the 12" version and testing it. If it's bad, take it back. For 1/10 the price of a Starrett, and made by a reasonably good company, it feels like a good risk to me.


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## woodnthings (Jan 24, 2009)

*how did you check it?*

First, an easy way is to use a draftsman's triangle. Locate them on a flat surface vertically and butt the edges together, looking for a gap at the bottom or top.

Second would be to do this:
http://www.newwoodworker.com/fxfrmsqr.html

Finally if the combination square is not "square" you can fix it ..possibly? You would have to work on the base, not the short edge.
If you use a feeler gauge under the base to make it square, that's how much you'd have to grind off. It may not be very much.

There may also be a protrusion on the blade that's causing it to travel unevenly. Finally,and most unlikely the blade itself is not parallel.

While not known for their quality Harbor Freight has a variety of squares and you can check them in the store by comparing two side by side or butting them together:
http://www.harborfreight.com/catalogsearch/result?q=squares


I have a set of these: http://www.harborfreight.com/3-piece-l-square-set-with-levels-98556.html

Like was mentioned, it all depends on how much precision you think you need. In woodworking, where the wood moves, accuracy to .001 may not be practical.
However, an 1/8" in 12" is not acceptable.


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## BZawat (Sep 21, 2012)

woodnthings said:


> First, an easy way is to use a draftsman's triangle. Locate them on a flat surface vertically and butt the edges together, looking for a gap at the bottom or top.
> 
> Second would be to do this:
> http://www.newwoodworker.com/fxfrmsqr.html
> ...


For my money, 1/32" out over 12" is unacceptable. I saved up and bought a Starrett that i found used in great shape. But I'm rather OCD so...


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## FrankC (Aug 24, 2012)

Cost has nothing to do with it, a cheap accurate square will yield the same results as an expensive accurate one. Depends how and where you are using it, if it is in the shop on a bench then go with the Starret, if it is on the job in your tool belt go with a reasonable priced one.


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## GISer3546 (Jan 30, 2013)

Its in a shop and will not leave my bench. I mostly do furniture building.


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## reynoldston (Sep 13, 2013)

Through the years I have bought a number of commination squares and I have found them not the most accurate but I have found different uses for them other then a square. I use the standard fixed square and have them in different lengths and find them more accurate then the commination square.


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## amckenzie4 (Apr 29, 2010)

Reading this thread reminded me I hadn't actually CHECKED that Empire 16" recently. It's one of their "True Blue" line, and despite being dropped a few times, it's still in square to the limits of my ability to test.

Not bad for a ~$15 square. As best I can figure, I probably bought it four or five years ago, but it may have been more. I know a lot of people seem to judge worth by cost, but I have to admit, I just don't see a more expensive square being of more value to me. Etched markings, lifetime guarantee (unless you've managed to bend the frame... they won't cover that), and quite solid. Actually, I'm thinking of replacing my 6" square now that I've looked at Empire more closely... It works, it's square, but it's marked in both inches and millimeters, and it gets confusing.


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## GISer3546 (Jan 30, 2013)

This square will be limited to my work bench mostly if not exclusively for furniture building. I did see a harbor freight had a 12" combo squares for $8... Im skeptical to say the least but might just go get a feel for them and check a few against each other to see. I'd give it a %5 chance that I'll leave with something but cant hurt to check.


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## Masterjer (Nov 6, 2012)

I started with the HF square, but quickly tossed it. The tab wouldn't ride securely in the groove so Jen I would tighten the screw, the tab would pull out if he ruler thereby making it pretty worthless. I picked up a Wood Ricer combo square and have been very happy with it. The construction is so much more solid and you can tell its a much better built tool.


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## ryan50hrl (Jun 30, 2012)

GISer3546 said:


> This square will be limited to my work bench mostly if not exclusively for furniture building. I did see a harbor freight had a 12" combo squares for $8... Im skeptical to say the least but might just go get a feel for them and check a few against each other to see. I'd give it a %5 chance that I'll leave with something but cant hurt to check.


You can get one of empires guaranteed to .001 combo squares for 10-12 bucks...don't waste 8 only to upgrade it later. The empire squares are top notch.


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## BWSmith (Aug 24, 2010)

Pull the threaded,thingy(technical term) that does the holding on the blade,and look at it.If it's "pot metal",it just isn't going to stand up to the daily use of a pro-shop and maintain accuracy.

Only the end user can decide what is in the best interest of their shop.Pot metal may work great for years?But when you can get old combo sqs for reasonable money used.....well,whatever.Carry on.


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## cabinetman (Jul 5, 2007)

Here we go again. Checking tooling in thousandths. If you want to use those fancy gauges I would first send them out to a tool and die maker to have them checked for accuracy. In fact, I would send them to three different shops and compare the results. That way you will have data to evaluate. 

But, I would be very careful in handling those gauges. They are precision instruments, and sudden movement could throw them out of calibration. Try not to jar them or drop them, and use only in a dust free environment, at ambient temperature and humidity levels suggested by the instrument manufacturer. I would wear cotton gloves so body warmth and skin moisture won't affect their performance.

Or, go to a box store and buy a Stanley. I've bought several over the years and all have been accurate. When adjusting the length, loosen the knurled nut, and slide the ruler part where you want, and press the ruler down to the base, and tighten the nut.

You can easily check for an out-of-square condition by placing the ruler flat on a substrate, with the flat part of the base on the edge, and draw a line. Then flip it over and do the same thing, about a ¼" away. Then look to see if the two lines are parallel.

Keep the all parts clean, including the groove and tab that slides in it.


















.


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## GISer3546 (Jan 30, 2013)

Masterjer said:


> I started with the HF square, but quickly tossed it. The tab wouldn't ride securely in the groove so Jen I would tighten the screw, the tab would pull out if he ruler thereby making it pretty worthless. I picked up a Wood Ricer combo square and have been very happy with it. The construction is so much more solid and you can tell its a much better built tool.


Right you are, with slightly more effort and cash i can get something to last forever.


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## Gilgaron (Mar 16, 2012)

I think Empire makes at least some of the Craftsman squares, you can probably drop by a Sears and inspect a few.


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## BWSmith (Aug 24, 2010)

Cabman,what gages are you talking about?I thought the thread was about combo-squares?


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## cabinetman (Jul 5, 2007)

BWSmith said:


> Cabman,what gages are you talking about?I thought the thread was about combo-squares?


Whatever gauges were used to determine this...



ryan50hrl said:


> You might check out the new empire squares guaranteed square to .001. I bought one for 15 or so and it's dead on....



















.


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## Gilgaron (Mar 16, 2012)

Cab man is being a little tongue in cheek, but makes a good point. Standards used for calibration should not be used regularly, and if you're looking for extreme precision should only be referenced in a known environment. 

He then goes to recommend against worrying about it to that degree. I tend to agree... if my combo square it a little off, it won't matter too much because I'm either going to cut that line with a table or miter saw which add more error, or if I decide to use my hand saws, it certainly isn't going to matter if my square was off by .0001 or .00001...


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