Precision Square For Tool Setup

ConwayCustoms

Rory
Senior User
Ladies and Germs,

I believe every "precision" square I've bought is not precise and I'd love some input on where to go and look.

I've bought everything from Kinex 875/0 (2 piece) to PEC, Bridge City (own all 3 of their expensive squares), INCRA Precision Square, Woodraphic (Made in Korea), etc.

I'm sick and tired of spending $$$$, or $.. on "precision" squares that I can't tell if they are precise, since none of my squares seem to be 99% - 100% accurate. Sure, I could draw the line down the square, then flip the square over, test.. but that doesn't seem to be "accurate" enough for me.. It might be 99.8% accurate.. but I am @nal and over overanalize my accuracy of tools as well as projects and when my cuts\tools are 99% accurate... (close but no cigar) I get frustrated\angry and want to throw woodworking to the side and never look back.

I'd love to have a square that I 100% know is 100% accurate/square, but who knows anymore. :\

I'd love a nice 100% accurate reference square, so I can set my other squares to it, so I can have all of my squares square.. but not sure where to look.

From my research... I've come to the understanding that WP are pretty good, but not "the best" and not 100% accurate. I didn't want to buy one of their SS squares and fall into the same pit that I've already fallen into.. numerous times over... so I've possibly decided on one of Starretts SS Square. It's a little pricey, but it is SS and, from what I've read, extremely accurate. Yes\No?


It IS $180, on Starrett's site, but if it is worth it... AND 100% accurate, I could most likely set my 4", 6", 8" Bridge City squares to it as well as tell if my PEC & Kinex are good for the garbage can or what. I also have a 12" T-Square & 24" T-Square, so hoping I could set those to 100% accuracy (99.99% would be acceptable :p ), too.. with whatever precision square I end up with.

Is Starrett worth that hard look, and $$$$, or should I look elsewhere?

If Starrett is worth the hard look & $$$$, where should I buy one (any specific website)?

Is this version of Starrett the "best" (2 piece?).. or do they make a solid 1 piece that might be a better choice?

I came across their Master Precision square, but I think that is way too much $$ and no way in h3ll I could justify the $$$$$$$ or owning that tool.


Thank you in advance.. and if you have any questions that would help you to better point me in the best direction... please feel free to ask.

Rory
 

Mike Davis

Mike
Corporate Member
This is what I have and use for machine set up and reference. Seems they went up a little since I got mine. I think I paid less than $100 about 20 years ago.


I also have a smaller one that I bought at a pawn shop about 15 years ago for $20. I use it for checking plane blades and other small stuff.
 

Mike Davis

Mike
Corporate Member
I pretty much buy anything I see at pawn shops, flea markets, antique shops, and e-bay that is made by Starrett, in good condition, and very low priced.
 

ConwayCustoms

Rory
Senior User
This is what I have and use for machine set up and reference. Seems they went up a little since I got mine. I think I paid less than $100 about 20 years ago.


I also have a smaller one that I bought at a pawn shop about 15 years ago for $20. I use it for checking plane blades and other small stuff.
Oh my!! $400?! Ha. Wow!

If it truly is that accurate, I'd snatch it up in a heartbeat... But $400? Is this a lot better, especially with accuracy, when compared to the square I mentioned earlier?

$180 vs $400..

Tool maker vs Master Precision

Thanks and I'll also keep my eyes open for the places to buy used Startetts.
 

tvrgeek

Scott
Corporate Member
Are you expecting too much? A strait edge and a knife scribe can measure a couple thou over 6 inches if very careful, but back to back on a surface plate looking for light can do better. I suggest testing all yours against each other on a plate to get a better idea. You can't mark against an edge with a scribe better than a couple thou. so that may not be a good method for verifying setup tools.

The list of expensive ones you bought are all going to be within their spec. For sure Bridge City is guaranteed. To be much more square than that, you would need to handle it in a environmentally controlled space and wear insulated gloves as your fingers would warp it. You are not going to buy better than half a thou over six inches.

Just made a new saw sled. Setup with the 5 cut method. I can crosscut, flip one side, and back to back no light. Good enough. I set up my Lyon trimmer 45 and can do 8 miters, put them together and have visually perfect joints in 3 inch wide styles. I think I am there on my 45 degree shooting board. Both more consistent than my miter saw.

FWIW, I have a Kinex, PEC, Incra, Post triangle, and Japanese style. All square against each other. One of my 12 inch plastic speed squares was good, the others I tuned. I tossed several cheap combination squares. I just got a vintage 6 inch try-square and though not perfect, good enough for joinery layout. I am not sure I would pay much for a used Starrett as if it was dropped, it may be bad. New you know, used you don't. Oh, a set of 1-2-3 blocks I believe to be square and I was surprised, a set of those corner glue-up red aluminum angles from China were very good though after a few uses, I doubt they will stay "set-up" true.
 

ConwayCustoms

Rory
Senior User
Are you expecting too much? A strait edge and a knife scribe can measure a couple thou over 6 inches if very careful, but back to back on a surface plate looking for light can do better. I suggest testing all yours against each other on a plate to get a better idea. You can't mark against an edge with a scribe better than a couple thou. so that may not be a good method for verifying setup tools.

The list of expensive ones you bought are all going to be within their spec. For sure Bridge City is guaranteed. To be much more square than that, you would need to handle it in a environmentally controlled space and wear insulated gloves as your fingers would warp it. You are not going to buy better than half a thou over six inches.

Just made a new saw sled. Setup with the 5 cut method. I can crosscut, flip one side, and back to back no light. Good enough. I set up my Lyon trimmer 45 and can do 8 miters, put them together and have visually perfect joints in 3 inch wide styles. I think I am there on my 45 degree shooting board. Both more consistent than my miter saw.

FWIW, I have a Kinex, PEC, Incra, Post triangle, and Japanese style. All square against each other. One of my 12 inch plastic speed squares was good, the others I tuned. I tossed several cheap combination squares. I just got a vintage 6 inch try-square and though not perfect, good enough for joinery layout. I am not sure I would pay much for a used Starrett as if it was dropped, it may be bad. New you know, used you don't. Oh, a set of 1-2-3 blocks I believe to be square and I was surprised, a set of those corner glue-up red aluminum angles from China were very good though after a few uses, I doubt they will stay "set-up" true.
I might be expecting too much, but who knows. Sure, when you glue\clamp, those tiny\hair line gaps will go away, or should, but I don't know anymore.

My 4" squares appear to be accurate, or very close, but my 8" square seem to deviate towards the 6"+ mark.. just a little, but that is too much for me, especially with larger pieces of wood & larger projects.

I bought all 3 of the Bridge City, in each size, and when I received them.... I couldn't tell which one was accurate. I 100% know at least 2 were not "precisely" square. I did the line test, as well as put one on top of the inner blade, outside blade.. etc.. and all 3 inside and outside of one another and I could see tapered gaps.. line tests were horrid, etc. I reached out to Bridge City and they said not to return them, but instead, use one as a reference (how could I when I had none I was confident in) and adjust the other 2 as needed. Well, when I tried that, I had to unscrew those 4 screws, and well.. now.. I really am not confident in any of the 3.

I bought a 9" PEC (not cheap, but not Starrett prices) to use that as a reference, so I could put those Bridge City squares back to where they should be..., but that PEC too seems to be off more than a 1/64th towards the 5"+ mark. As you go further down the square, that 64th turns into a greater deviation and well.. since I can't make adjustments to that PEC.. it ticks me off and I just want to chuck it in the trash.

I bought that 6" Kinex to verify if that PEC was truly garbage at the 5"+ mark.. and both the Kinex and PEC had angled gaps in them, so I couldn't trust either the PEC or Kinex, since I couldn't tell if 1 was square vs the other. No confidence in the PEC and Kinex.

I don't want to buy another square, thinking that one IS indeed square, just to find out I was bent over.. again.. on marketing and false hope. :(

I'm OK with trying 1 more square.. Starrett or whatever.. but that WILL be it.

I believe Woodp3ckerz owns BlueSpruceToolworks, but those "appear" to be of better quality and more precise? Anyone have any experience with Blue Spruce Toolworks? Should I give them a chance or just get that $180 (might be slightly cheaper on a dist. site) SS Starrett (6" square)?

Thanks for your input\experience...

R.
 

Charles Lent

Charley
Corporate Member
A drafting triangle is a good cheap source for accuracy, but when about to use one of my squares for anything I pull out one of my 1-2-3 blocks and check the square against it. This is far accurate enough for anything that I've needed in woodworking.

Charley
 

ConwayCustoms

Rory
Senior User
Any recommendations on a drafting triangle (plastic.. stainless...)?
6"...12"? Get both "smaller" & "larger" drafting triangles?

And what about 1-2-3 blocks (which one\s...buy from where)?

I'd like to get all 3 of my Bridge City squares in square, as well as get my 12" - 24" "precision" T-Square in square... if possible.. after setting my 8" Bridge City square back in square and using that to get the 12" T-Square in square.


Frustrated and the thought of quitting woodworking has crossed my mind.. about 5% - 10% :\

Thanks again!
 

Mike Davis

Mike
Corporate Member
I might be expecting too much, but who knows. Sure, when you glue\clamp, those tiny\hair line gaps will go away, or should, but I don't know anymore.

My 4" squares appear to be accurate, or very close, but my 8" square seem to deviate towards the 6"+ mark.. just a little, but that is too much for me, especially with larger pieces of wood & larger projects.


Thanks for your input\experience...

R.
You are welcome to come check all your squares against my Starrett, my 1,2,3 blocks, my cast iron block square or anything else I may have. Maybe then we will both doubt all our squares...
 

ConwayCustoms

Rory
Senior User
You are welcome to come check all your squares against my Starrett, my 1,2,3 blocks...... Maybe then we will both doubt all our squares...
Thank you.... and I'd hate to put that thought in your mind. You'd have a lot of sleepless nights and I just couldn't live with that, knowing I caused you such pain. :p
 

ssmith

Scott
Senior User
You can’t go wrong with Starrett – we serviced thousands of their tools every year in my previous “profession” LOL. They’re reliable and do meet their specs, out-of-the-box. Buying used may be a good option too if you can be sure it wasn't abused.

Having said that and looking at your list there are a number of other manufacturers, so I checked around a bit and was a bit dismayed at what’s out there. You really do need to watch the specs. A few samples of 12”-ish squares:

PEC, $92
Spec: SQUARENESS Inside and Outside Angle: 0.0010″
Technically, that’s ambiguous because they don’t cite a recognized standard (like DIN 875) and don’t say what that number actually means. Can it be “off” by 0.001” at the end of the blade, or off by 0.001” per inch from the corner?

Veritas, $69
Spec: 0.001" per inch of length
Their spec makes sense, and this is a pretty good, inexpensive square ($69) but you’d have to be OK with a 0.012” gap at the end of a 12” crosscut.

Starrett, $800
Spec: 0.0001 per 6” of length
Their spec makes sense, max errror would be 0.0002" at the end. 60X more accurate than the Veritas square but wow, $800 hurts.

Kinex, $70
Spec: DIN 875/0, equivalent to 0.00043” at the end of the long leg (300 mm).
That’s actually a really good value – DIN 875 specifies both worst case error at the end of the blade, and the maximum error (linearity) along the length of the blade. DIN 875 Spec.

Given all that, the Kinex looks like a really good deal, and I’m tempted to pick one up myself. I’m curious though given your comments about it, since I’ve never owned one of their products. Aside from the comparison to your PEC square, do you have other reasons to question it’s squareness?
 

tvrgeek

Scott
Corporate Member
Rory, you are welcome to check against mine. I am closer to you than Mike. (In Hillsborough)
 

ConwayCustoms

Rory
Senior User
You can’t go wrong with Starrett – we serviced thousands of their tools every year in my previous “profession” LOL. They’re reliable and do meet their specs, out-of-the-box. Buying used may be a good option too if you can be sure it wasn't abused.

Having said that and looking at your list there are a number of other manufacturers, so I checked around a bit and was a bit dismayed at what’s out there. You really do need to watch the specs. A few samples of 12”-ish squares:

PEC, $92
Spec: SQUARENESS Inside and Outside Angle: 0.0010″
Technically, that’s ambiguous because they don’t cite a recognized standard (like DIN 875) and don’t say what that number actually means. Can it be “off” by 0.001” at the end of the blade, or off by 0.001” per inch from the corner?

Veritas, $69
Spec: 0.001" per inch of length
Their spec makes sense, and this is a pretty good, inexpensive square ($69) but you’d have to be OK with a 0.012” gap at the end of a 12” crosscut.

Starrett, $800
Spec: 0.0001 per 6” of length
Their spec makes sense, max errror would be 0.0002" at the end. 60X more accurate than the Veritas square but wow, $800 hurts.

Kinex, $70
Spec: DIN 875/0, equivalent to 0.00043” at the end of the long leg (300 mm).
That’s actually a really good value – DIN 875 specifies both worst case error at the end of the blade, and the maximum error (linearity) along the length of the blade. DIN 875 Spec.

Given all that, the Kinex looks like a really good deal, and I’m tempted to pick one up myself. I’m curious though given your comments about it, since I’ve never owned one of their products. Aside from the comparison to your PEC square, do you have other reasons to question it’s squareness?
Maybe it is not the actual product; PEC, Kinex.. but rather where I am buying them from?

I bought 2 PECs from mbemrocatalog, which recently changed to egcsupply, and the one Kinex from Amazon.

From all of the squares I currently own: PEC 4", PEC 9", Kinex 6", Bridge City 4", 6" 8"
I'd say my Kinex 6" is the "most" accurate, but still has deviations I am not 100% happy with, even 99% happy with.

I see the Starrett Tool Maker Square and Master Precision, but I do not believe the tolerance difference, from the Tool Maker vs Master, is worth the extra money. At least, to me.. Maybe if you purchase the longer square\s.. 12"+?

From Starrett's website:

Toolmakers Stainless Steel Square: is high quality, is not graduated and offers squareness accuracy to 0.005mm (.0002" ) for every 150mm (6"). $180
Master Precision Square: is the finest precision-checking square. Squareness accuracy to .0001" (0.0025mm) every 6" (150mm). $400

The 12" Starrett's are too much for me, mainly the Master Precision version ($800-ish). The Toolmakers Square is more "reasonably" priced, but right now.. I'd much prefer the 6". This way, I'd hope I could adjust my 3 Bridge City squares to be very accurate, heck, d@mn near perfect. If\when I can dial in my 3 Bridge City's.. I should be good on most tools alignments & projects for a good while.

If I do decide on that 6" Starrett toolmaker square, any particular place\site I should buy it? Directly from Starrett? or...

Thanks again!
 

Oka

Board of Directors, Vice President
Casey
Staff member
Corporate Member
You could have a precision shop calibrate them. Had 3 done cost a hundred bucks..... another option
 

Wiley's Woodworks

Wiley
Corporate Member
This a great thread. Lots of good ideas on how to solve your dilemma, but so many, including your solutions, involve purchasing more tools, and you've got way more than any single woodworking shop needs.

I rely on plastic draftsman's triangles to set critical angles and calibrate my measuring tools, and I will admit I have never tested them to .0001 +/- tolerances. Weather doesn't affect them, and they can't be knocked out of square. If you can find a positively known perfect square (I am shocked that 3-2-1 blocks are not square to your specs), what about laying a digital angle finder on it and then make compensations off of its deviance from 90.00. BTW is there a digital tool of any type that has an adjustable reading? I am slowly migrating to digital tools because of my old man eyesight, and so far they have functioned acceptably for me.
 

Hmerkle

Board of Directors, Development Director
Hank
Corporate Member
Rory,
If I were you I would get a quote from a tool and gauge shop. (Oka beat me to the punch) (We have a number of them here in Greenville SC that I have used in a past life...)
I found one in Wake Forest: North Carolina Instrument Calibration Services | IQS
By searching "calibration testing wake forest" you might want to make the search a little broader and make some phone or e-mail inquiries. I am SURE the costs and the capabilities vary from company to company...
1. YUP, that "square" sucks and is only a square in name
2. YUP, it is out by .006 over 6 inches for another $$$ we can make it right...

Remember at the level you are talking about heat and humidity can have an effect on the accuracy of that tool.
you need to match the temperature and humidity of the testing facility with the "Gauge" in use...
 

Graywolf

Board of Directors, President
Richard
Staff member
Corporate Member
I’m curious, are you building things out of wood? The most imperfect material you can find to build with. I have built many a piece with squares far less accurate than any of those with visually no gaps in the joinery and unless you want to go over it with a microscope visually you will find no issues. Are we hopelessly over obsessed with precision? What price in money, and time is precision worth? I have several squares and the most expensive one is a Starrett combination square one Wood Pecker and the rest are older than I am. I work with the antiques more often then any of the others. What I was taught when I first started woodworking was pick a square and trust it. An individual working with his tools and trusting them makes a big difference.
 

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