# Carpenters square wayyyy off



## allpurpose (Mar 24, 2016)

I never realized just how far off it is till now. I have it and an extruded aluminum speed square which I'm pretty sure is still square, but I was working on a new cross cut sled and the two sides were never in square dispite the fence being flat and the cut being straight. I flipped the carpenter square and it was always wrong..I was going batty.. Then I checked it against the speed square and in just 6" it's off about 1/16th. The speed square is dead on on the sled, but the carpenter square...holy moly! About 1/4" whenever I flip from one end of the cut to the other.. Needless to say the carpenter square is junk.. Absolutely useless for its intended purpose.. Glad I figured this out now instead of wasting untold lumber or building a room addition or something..


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## hwebb99 (Nov 27, 2012)

Calling a tool a square doesn't make it square.


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## woodnthings (Jan 24, 2009)

*yoiu can fix an out of square square*

How to fix your unsquare square:


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## epicfail48 (Mar 27, 2014)

Ive had the same issue, exact same actually. Built a new sled god knows how long ago, and for the life of me I could never get the bugger square, until I realized that my square wasn't square. 

Needless to say, I don't much trust framing squares anymore. Wasted way too much time on that one


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## GeorgeC (Jul 30, 2008)

It is too easy to check the "squareness" of a square in the store. I would not think of buying a new square without first checking it.

George


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## Hammer1 (Aug 1, 2010)

Very common for squares to not be square. Every shop needs an accurate reference square. It is used for setting up machinery and checking other squares. You can buy a 6" engineer's square for cheap and it can change your life. 
Here is just one example. https://www.amazon.com/Robert-Larson-885-1006-6-Inch-Engineer/dp/B0012XU112


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## Steve Neul (Sep 2, 2011)

I've never had any luck re-squaring a framing square. Yes they can be made square but it seems like they easily go out of square again. Best to find an open field somewhere and practice your boomerang skills.


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## m.n.j.chell (May 12, 2016)

I use my little 9"x12" square, but I rarely use the full sized one. I'll have to check them all, now, though. And my T-square and combination squares, too, I suppose.

Thanks for creating the extra work for me, AllPurpose !!!


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## FrankC (Aug 24, 2012)

The center punch method basically fine tunes the square, I think 1/4" is expecting too much.


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## m.n.j.chell (May 12, 2016)

If you use a center punch to true the square, doesn't that also put bulges on the straight edge ... requiring filing to remove them?


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## Jammer (Jul 15, 2009)

No. And those marks are in the wrong place.

FrankC, I suspect he's looking at 1/8" error, which would show up as 1/4" on a test.


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## m.n.j.chell (May 12, 2016)

Jammersix said:


> No. And those marks are in the wrong place.


"Those marks" are exactly where he was showing in the video if the arm needed to move "outward." 
If it moves enough metal to push the whole arm out a good fraction of an inch, why does it not also move metal directly to the weakest point, the closest edge?
I am not being argumentative. When we punch lock screws on oil pump covers, we're driving metal out from the edge of the screw, enough to also deform the aluminum of the cover. That screw isn't coming out without a lot of force (more than it's torqued to).

Just seems, to me, that the same thing would happen on the square.


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## allpurpose (Mar 24, 2016)

Metal stretches and isn't always easy to unstretch. In auto body work we used heat to bring dings such as hail damage up then shave it off with a body file. i suspect that the divets do about the opposite pulling the steel back.. At any rate it's a bit closer than it was, but right now I have a shortage of square panels to check against. The only one I have available is long enough, but only about 14 inches wide so I guess I'm due for a trip up to big orange or blue someday.. in the meanwhile the sled seems to be ok.. I made the 5 cuts and it's not perfect, but pretty darn close. I'll do some more work on it when I'm sure I have a reliably square edge to reference from.


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## Brian(J) (Feb 22, 2016)

Jammersix said:


> No. And those marks are in the wrong place.
> 
> FrankC, I suspect he's looking at 1/8" error, which would show up as 1/4" on a test.


To me, people spend way too much on cars and not nearly enough on tools, because the enjoyment of using the better tools is so much higher than for the cheap ones, plus a lot less time and thought invested in overcoming the crap factor.
With that in mind, a Lamb Square is a delight to use, and does a lot more than just square.
http://www.lambtoolworks.com/products.html


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## FrankC (Aug 24, 2012)

Brian(J) said:


> To me, people spend way too much on cars and not nearly enough on tools, because the enjoyment of using the better tools is so much higher than for the cheap ones, plus a lot less time and thought invested in overcoming the crap factor.
> With that in mind, a Lamb Square is a delight to use, and does a lot more than just square.
> http://www.lambtoolworks.com/products.html


What you show is not a framing square, or as some call it a carpenters square. Checking for 90 degrees is only a fraction of what this tool is used for.

http://doit101.com/Steelsquare/steelsquare.htm


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## Hammer1 (Aug 1, 2010)

woodnthings said:


> How to fix your unsquare square:
> Check and Repair a Framing Square - YouTube


This method for correcting a framing square is a holdover from the days when framing squares were made from steel and had tapered "legs", thicker at the corner, thinner at the leg ends. It does not work on non tapered legs or aluminum squares. You can split open an aluminum framing square doing this.


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## woodnthings (Jan 24, 2009)

*I don't own an aluminum framing square.....*

But if I did, and found it was unsquare. by a small amount, I would draw file it to make the correction, checking it often as I worked the metal away. You could accomplish the same with steel one, but it would take more effort. 











I don't know what effect heating the heel area would have and if it would just bend to a correct amount.... BUT an unsquare square is worthless regardless, so it would still be worthless even if it didn't work... just sayin'.


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## Hammer1 (Aug 1, 2010)

woodnthings said:


> But if I did, and found it was unsquare. by a small amount, I would draw file it to make the correction, checking it often as I worked the metal away. You could accomplish the same with steel one, but it would take more effort.
> 
> 
> 
> ...


If you file the leg or tongue, you will have to file both inside and outside or only one side will be square. The width of the leg and tongue will not be parallel through their length. Might as well toss bad squares or they will haunt you!

Back in the day, carpenters used to "hang" their squares by stabbing the corner into a stud. After awhile, this would stress the corner and knock it out of square, sometimes breaking it. The heavy steel squares are also used as ice scrapers. In the winter, you can't even mark a pencil line across a joist due to a thin layer of ice. We kept the edge of our squares filed with a nice square, sharp edge for this purpose.


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## FrankC (Aug 24, 2012)

Hammer1 said:


> This method for correcting a framing square is a holdover from the days when framing squares were made from steel and had tapered "legs", thicker at the corner, thinner at the leg ends. It does not work on non tapered legs or aluminum squares. You can split open an aluminum framing square doing this.


Well now that the word has come down on that, despite it being a common blacksmithing technique, it will be a big job editing the entire internet.:smile3:


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## Jig_saw (May 17, 2015)

I checked the 'squareness' of my 6" steel square against the digital protractor I just bought. It showed 89.7 deg. on the outside. Is that square enough?


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## m.n.j.chell (May 12, 2016)

Jig_saw said:


> It showed 89.7 deg. on the outside. Is that square enough?


.3 degrees is within human error, depending on what you're using to give you that reading.

This is the easiest way to be sure ... like the above video shows.
I drew it with MSPaint, so the "board" isn't long enough, I know (sue me) ... but the process is true, as long as the edge you put the square on is true.


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## FrankC (Aug 24, 2012)

Jig_saw said:


> I checked the 'squareness' of my 6" steel square against the digital protractor I just bought. It showed 89.7 deg. on the outside. Is that square enough?


It is only square if it measures exactly 90 degrees. It may be close enough, how do you know your digital protractor measures dead on?


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## Jig_saw (May 17, 2015)

FrankC said:


> It is only square if it measures exactly 90 degrees. It may be close enough, how do you know your digital protractor measures dead on?


Correct. We can only measure one tool against the other without knowing which one is 'true'. Same with human eyes. Things look square to us when they are not.


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## woodnthings (Jan 24, 2009)

*You can check you digital protractor also*

Use the same method as posted above for a framing square. Set the protractor to 90 degrees on the indicator, scribe a line, flip it over and scribe another line. If the lines are parallel, you're good to go. If not, the correction must be 1/2 of the difference. I don't know if digital protractor are adjustable.....?:nerd2:


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## Jig_saw (May 17, 2015)

woodnthings said:


> Use the same method as posted above for a framing square. Set the protractor to 90 degrees on the indicator, scribe a line, flip it over and scribe another line. If the lines are parallel, you're good to go. If not, the correction must be 1/2 of the difference. I don't know if digital protractor are adjustable.....?:nerd2:


Yes, we can reset the zero angle. But no two lines are ever exactly parallel in my experience. They have to be drawn on a flat table, but no table is exactly flat! Then the pencil we use must be held exactly vertical when scribing, which also never possible (hand shakes a little while drawing straight lines).

Nothing we humans do is ever perfect or exact:
_Errare humanum est_ (to err is human)


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## woodnthings (Jan 24, 2009)

*really?*



Jig_saw said:


> Correct. We can only measure one tool against the other without knowing which one is 'true'. Same with human eyes. Things look square to us when they are not.





Jig_saw said:


> Yes, we can reset the zero angle. But no two lines are ever exactly parallel in my experience. They have to be drawn on a flat table, but no table is exactly flat! Then the pencil we use must be held exactly vertical when scribing, which also never possible (hand shakes a little while drawing straight lines).
> 
> Nothing we humans do is ever perfect or exact:
> _Errare humanum est_ (to err is human)


How do you get anything done if that's your "world" view? At some point don't you just have to say "That's close enough for me" ..... or NOT? :frown2:


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## GeorgeC (Jul 30, 2008)

Jig_saw said:


> Yes, we can reset the zero angle. But no two lines are ever exactly parallel in my experience. They have to be drawn on a flat table, but no table is exactly flat! Then the pencil we use must be held exactly vertical when scribing, which also never possible (hand shakes a little while drawing straight lines).
> 
> Nothing we humans do is ever perfect or exact:
> _Errare humanum est_ (to err is human)


WOW!!!
"Nothing we humans do is ever perfect or exact:"

Maybe not, but it sure is close enough that another human cannot argue against it.

George


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## GeorgeC (Jul 30, 2008)

Jig_saw said:


> Correct. We can only measure one tool against the other without knowing which one is 'true'. Same with human eyes. Things look square to us when they are not.


Not correct. There are methods of checking instruments (squares) that do not require measurement against another square.

This is also one of the reasons that the National Institute of Standards and Technology  exists. 

One of the things that it does is maintain a collection of certified devices.

George


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## Jammer (Jul 15, 2009)

Light is perfect.

If two boards are cut at 90 degrees, not even light can find a way through.

If two boards are not 90 degrees, there will be an orientation that lets light through, and there will an orientation that is twice the error. Sometimes the two are the same, which is what I would expect from eighty-nine point something degrees.

(A decimal is the crudest method to divide a degree.)


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## m.n.j.chell (May 12, 2016)

Jig_saw said:


> hand shakes a little while drawing straight lines


While I don't disagree with the general concept you're trying to say ... I do have issue with this line, at least ... 
I can draw a near perfect straight line or circle freehand.

Using a pencil, I can legibly write ON the blue line of legal paper. 

While humans are unflaggingly error prone, we can produce perfection here and there.


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## Jig_saw (May 17, 2015)

woodnthings said:


> How do you get anything done if that's your "world" view? At some point don't you just have to say "That's close enough for me" ..... or NOT? :frown2:


Well, we have to be realistic. And yes, at some point we have to accept and say 'that is close enough'.

But what is close enough for me may not be close enough for you (and vice versa). There is no single objective standard by which we can measure everything. For example, the exact meter scale is kept at a 'constant' temperature in a museum in Paris. But how do we know the temperature is indeed held exactly constant, and that there are no tiny variations?

My point is we as humans must accept what can be achieved by us rather than strive for some ideal perfection which exists only in our minds.


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## Jig_saw (May 17, 2015)

Jammersix said:


> Light is perfect.
> 
> If two boards are cut at 90 degrees, not even light can find a way through.
> 
> ...


Light may be perfect, but our perception of light is NOT. How do we know the 'light is not going through the gap'? Have you looked at a gap under electron microscope which appears to the naked eye as sealed?


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## woodnthings (Jan 24, 2009)

*bull feathers!*



Jig_saw said:


> Light may be perfect, but our perception of light is NOT. How do we know the 'light is not going through the gap'? Have you looked at a gap under electron microscope which appears to the naked eye as sealed?


Back away from the electron microscope and join the rest of us in the real world of woodworking, where joints are made with as much precision as needed to look right and to create a good glue bond. Closer than that don't matter to us..... just sayin'. :smile3:


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## Stevedore (Dec 28, 2011)

Many years ago, I made a minor correction by judicious hammering on one of my steel framing squares (with,gasp, non-tapered legs!), and it worked fine. Still fine the last time I checked it.

On a related note, I was once buyng a 12" try-square at Sears, and the salesman cautioned me to check it for squareness, saying "A lot of these aren't that square". He actually took a few over to a table saw with me, drew lines & flipped squares to make sure the one I was buying was as close as we could see. I suspect that he was a woodworker.

My only regret is that I didn't have my electron microscope with me that day!


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## Jig_saw (May 17, 2015)

Well, we have to be realistic. And yes, at some point we have to accept and say 'that is close enough'.

My point about electron microscope is that nothing in nature is ever 'perfectly' straight or square. But we have to accept what we get as humans.

What is straight/square for a woodworker may not be so for a machinist. On the other hand, what a machinist can claim to be square can be demonstrated by a scientist as not square!

So everything is relative, including accuracy of our instruments. Don't go looking for a microscope if you are a woodworker, and don't go complaining that your carpenter's square isn't 'square'. But don't expect 'perfection' in woodworking either.:thumbsup:

My quibble is with people who want exactness and perfection. There is no such thing in life.


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## Jammer (Jul 15, 2009)

That's a common fallacy.

Carpenters and furniture builders regularly produce joinery and adjustments that would measure true to a machinist. What they don't do is _measure_ it as true.

Examples include jointers, Temple Joinery, and truing a saw. Results are results, waterproof is waterproof, light is light.

The fact that woodworkers don't _measure_ to the thousandth does not mean that the joint is not _true_ to the thousandth.

I've wondered before where such legends come from.


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## Jig_saw (May 17, 2015)

There is someone here in this forum who has a cool signature, such as "_Measurement is the enemy of accuracy_" (or words to that effect). I agree with that sentiment.

I think woodworking is more about aesthetics than about accuracy. But it is my personal opinion, and others can disagree.


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## epicfail48 (Mar 27, 2014)

Jig_saw said:


> There is someone here in this forum who has a cool signature, such as "_Measurement is the enemy of accuracy_" (or words to that effect). I agree with that sentiment.
> 
> I think woodworking is more about aesthetics than about accuracy. But it is my personal opinion, and others can disagree.


I'm pretty sure that quote is championing referential measurements over measuring to a number tape measure, not proclaiming that you shouldn't measure things.

Doesn't matter how good your projects look, if your cuts aren't square and your joints aren't accurate, even the fanciest build will rapidly collapse into a pile of crap. Just because we can't attain perfection doesn't mean we shouldn't strive for it, and in the case of this thread doesn't mean we should settle for a square that's really a 89 degree angle


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## woodnthings (Jan 24, 2009)

*I only measure when I have to ....*

When building a one off piece there is no need to fit into a confining space, so I just start with a length, height or a width dimension and progress from there.

For example, the sides of a quilt rack are really not that critical in width, just that they be the same. The location of the mortises can be approximated, but they must also be the same. I use stops on the RAS to make crosscuts of equal length. I use stops on the router mortising jig to locate the mortises in the same place. I make tenons to fit the mortises, by trail and error on the bandsaw adjusting the fence until I get a fit that's "just right" ... some drag, but not loose or a hammer fit. The actual dimensions don't concern me, it's the fit that matters. I design and build to a "fit" rather than a dimension, but that's just me. :nerd2:


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## Jig_saw (May 17, 2015)

epicfail48 said:


> I'm pretty sure that quote is championing referential measurements over measuring to a number tape measure, not proclaiming that you shouldn't measure things.
> 
> Doesn't matter how good your projects look, if your cuts aren't square and your joints aren't accurate, even the fanciest build will rapidly collapse into a pile of crap. Just because we can't attain perfection doesn't mean we shouldn't strive for it, and in the case of this thread doesn't mean we should settle for a square that's really a 89 degree angle


If my cuts/joints look square to me then they are square. I don't go measuring them. Many times experience is the best guide. Having made hundreds (if not thousands) of hand made joints, one can tell by looking if a joint is square or not. For example, a cabinet I have just completed has dozens of joints. If I apply a carpenter's square to any of them, they will not read exactly 90 degrees. Some are not even 89, and some may be more than 91! But they look square, and that is all that counts.

The only time I use a square is when handplaning a long piece when naked eye can't give the required information. But when the pieces are put together you can tell if the joints are square or not.


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## m.n.j.chell (May 12, 2016)

Got any pictures of that cabinet, Jig-Saw?


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## joeb841 (Aug 14, 2016)

Jig_saw said:


> I checked the 'squareness' of my 6" steel square against the digital protractor I just bought. It showed 89.7 deg. on the outside. Is that square enough?



I would question the digital protractor before the 6" steel square.


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