Vintage Brass/Steel/Rosewood Try Square Accuracy?

[Stew Denton]

Stevens post on "I guess I can use this" brought Try Squares to mind. I see old brass/rosewood/steel try squares on the auction site every now and then when I think about buying a large one. (I haven't bought a big one yet, but will likely have a 12" sooner or later.)

I do have one that belonged to my dad. It is a Stanley #20 in nearly new condition.

I checked it with one of my old drafting triangles a few years a go, and it was dead square, at least by my drafting triangle.

From my perspective, it looks like the old brass/rosewood/steel try squares were the premium models that they sold back then, there were all steel models, but they appear to be cheaper.

The question is, are a lot of these old premium try squares extremely accurate at 90 degree angles in your experience?

Thanks and regards,

Stew

[Jim Koepke]

I haven't bought a big one yet, but will likely have a 12" sooner or later.

The size designation on squares usually refers to the total length of the blade. A 12" wouldn't span the face of a 12" board.

One of my purchases on ebay was listed as an 18" square. That guy is big:

A Big Square.jpg

It may actually be a 20" model.

One to span a 12" board is also on my list of wanted tools.

jtk

[Brian Deakin]

Use the follooowing method to check for square

Please note you need to use a pencil with a sharp point to produce a fine line

https://www.youtube.com/watch?v=W-_6r7Rzqm8

[Derek Cohen]

Note that anything made of different materials and held together with pins will move. The only question is by how much?

If you want accuracy to be ongoing, the only squares to consider are made for machinists ... and this excludes combination squares, which are made for woodworkers. Even the best Starrett combination square will lose accuracy given enough time. Parts that move must wear.

At the end of the day you have to ask how much accuracy is important and, if it is very much so, then invest in a machinist or engineer's square. The wonderful thing about these is that they can be had quite cheaply from Lee Valley.

Or, if you have a woodworker's heart, and a deep pocket, get an infilled machinist square from Chris Vesper.



Regards from Perth

Derek

[Brian Holcombe]

The four cylinders method is one way. Another way is to check using a reference plate (surface plate) and a known square reference.

I like Starrett and Mitutoyo for squares, best to get one with a cert for use as a shop standard.

[Dave Anderson NH]

I'm with Brian on this one. I have a drawer in one of the red roll around Craftsman tool boxes containing reference tools. I have a 24" Veritas steel straightedge which I tested on the CMM at work for accuracy which was .001" over the 24" length. I also have a 6" Mitutoyo engineers square, dial and test indicators, and a Fowler 12" long jaw dial caliper. These tools only come out to calibrate other tools like my daily use calipers and squares. They are not used on projects or in any use where the might get damaged. They are reference only.

[steven c newman]

I just checked....the Stanley No. 20 I have in the shop...will reach out to 12" and will cross all the way across a 12" wide board....

Have about every size from that 12" No. 20 down to a 3" one..with 3 brass diamond shaped pins...even have a til...they share with the drills
Wooden Squares, the til.JPG
The Line up..
Wooden squares 1.JPG
Measurement?
Wooden squares, no. 20.JPG
12" from the brass side to the end of the blade..
Wooden squares, mitre squares.JPG
Stanley Rule & Level Miter squares, and
Wooden squares, bevel gauge.JPG
While we are on the Steel, Brass, & rosewood theme....

[Stewie Simpson]

This Is Hand Tool Woodworking


What is a gnat’s nadger?
It’s something very small. Smaller than a 1/64″?
Smaller than I would care to measure.

If you’re getting any smaller then it’s a gnat’s cock hair.

https://www.theenglishwoodworker.com...l-woodworking/

[Bob Glenn]

For what it's worth, I'm with Stewie on this one. It's hand tool wood working, nothing's perfect. If it looks good, it is good. No one notices the small stuff unless you point it out.

[steven c newman]

2 line method...simple, easy, quick. needs a jointed straight edge on a scrap of wood...
Check a square 1.JPG
You can separate the 2 lines a hair...makes it easier to see any differences...

[Jim Koepke]

This Is Hand Tool Woodworking


What is a gnat’s nadger?
It’s something very small. Smaller than a 1/64″?
Smaller than I would care to measure.

If you’re getting any smaller then it’s a gnat’s cock hair.

https://www.theenglishwoodworker.com...l-woodworking/

For what it's worth, I'm with Stewie on this one. It's hand tool wood working, nothing's perfect. If it looks good, it is good. No one notices the small stuff unless you point it out.

+1 on both of these.

2 line method...simple, easy, quick. needs a jointed straight edge on a scrap of wood...
Check a square 1.JPG
You can separate the 2 lines a hair...makes it easier to see any differences...

It also makes it easier to see the difference or even measure it with an inspection loop:

Search > inspection eye loop reticles <

Seeing or measuring variation of distance between two lines is easier than trying to get them to start at the exact same point and then see or measure. Start close and hopefully they stay close. Any variation is twice the error.

jtk

[Roger Nair]

In my experience, two factors weigh heavily on the accuracy front, how well the blade is fixed to the body and wear on the blade from striking or marking with steel tools. The old tools I have found have all had wear on the blade, luckily the blade is usually proud of the body and with considerable care a square reference can be marked and be filed and stoned to a close tolerance. Good luck.

[Derek Cohen]

I'd rather have an accurate square than a so-so square. It may be woodworking, but using inaccurate squares is a recipe for frustration.

Chris Wong and his Magic Square agree with me ...



Regards from Perth

Derek

[steven c newman]

And just who said mine aren't accurate?

[Rob Paul]

I like to shine up the brass and polish the rosewood on those beautiful old squares. I have a variety of different brass pin designs and blade sizes and have found most of these squares are pretty accurate (plenty accurate enough for woodworking).
If I find one that is slightly out-of-square when checking against my steel squares, I have always been able to correct this by holding the square by the wood part, and giving the blade a sharp whack onto my bench top to move it a smidgen in the desired direction.