Granite Square sourcing

justindavidow

justindavidow

(Justin)
Hey folks!

Anyone have a granite square? How do you like it?
and crucially: where did you get it?

I'm on the lookout for a 300x400x60mm (12x15x1.5") (ish; I am pretty flexible here!) granite square.

I'd really love to know if there are odd vendors that I should know about? Anyone come across a strange or unusual local (or at least Canadian?) vendor who produces squares?
 
Tom Kitta

Tom Kitta

Ultra Member
Many years ago (like 5 or 6) I got one at BB. Grade B accuracy 0.0001. Never tested it. IF one does not have one handy you can try other materials that are flat like glass panel.
 
P

PeterT

Ultra Member
Premium Member
Usually I've found if Shars sell something & they are Asian origin, it can usually be sourced elsewhere/at the source for a bit less.
www.shars.com

10" x 6" x 1" Precision Granite Square

www.shars.com www.shars.com
...but not here LOL

Precision Granite Products | CDTooling

www.carbideanddiamondtooling.ca

But I've noticed on some tooling lines Shars might have something approaching their own unique line, or at least not as prevalent. And they are also listing some USA tools, so its not a complete offshore store.
 
Dabbler

Dabbler

ersatz engineer
I tried to buy one from the US, but they wanted me to hire a US 'export broker' before shipping it. There's no such thing for granite items. I gave up on Standridge Granite.
 
Dabbler

Dabbler

ersatz engineer
A cylindrical square can be used in many situations as a substitute to a granire square. they are just no *quite* as precise, but very much good enough for a hobby or machine shop - about the same as a B grade granite square.

I should add the magnetic Suburban square has very few uses, and is no substiture for the granite square. The TTC cylindrical square is what can substitute, but a granite square can be had for less money - if you can find one.

For a hobby shop a precision metal square can suffice.
 
Tom Kitta

Tom Kitta

Ultra Member
Well you have a cylinder https://www.amazon.ca/Accusize-3-Cy...9Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

and you have actual granite


They both claim 0.0001 accuracy. The cylinder is a bit bigger but more expensive.

I am trying to make my own cylinder square. For it I actually need a grinder as polishing it with emery cloth introduces too much "roughness" I think I am right now just touch better then 0.001. Goal is to match +-0.0001. Compared to suburban tool this is very inaccurate.

Issues I am facing are for example the need to dress and grind the surface grinder wheel (for the ends) while moving - both operations, as my ends otherwise came out +- a tenth - I want less, a deviation 4x less. I though about scraping it BUT my B grade granite plate is only a tenth accurate itself. This was supposed to be "apprentice" level thing - but its not as easy as it seems. I also realize that its difficult to make too skinny and tall cylinder due to inability to deal with base flatness at least at my setup. A 3 to 1 ratio probably is the best - i.e. 2 in base - 6 in tall, 4 in base - 12 in tall.
 
Dabbler

Dabbler

ersatz engineer
I have seen the HHIP one before, but I've been reluctant - my trust level isn't at the 260$ risk point. The standridge one was around the same price, on their sale page.
 
Dabbler

Dabbler

ersatz engineer
The trick for a cylinder square is the rotary grind being even along its length. This is measurable by a mic, but is not as accurate as lapping in a granite square. As it is used with light, it is important to have a good finish with minimal deviations in diameter. Used pitted cylinder squares are poor performers.

A Starret or Moore and Wright Engineer's square is usually rated at .0002 end to end and square, which is a good substitute for a cylinder square or granite square in a hobby shop.
 
M

Mcgyver

Ultra Member
justindavidow said:
Anyone have a granite square? How do you like it?
and crucially: where did you get it?
Click to expand...
I don't, but depending on the need, there are alternatives.

I would be extremely cautious of anything except a recognized brand. We all know (or should) that the test claims of most low coast offshore suppliers are (sometimes/always/occasionally) market driven works of fiction. Now, its very often more than good enough for someone's needs, peace. However if someone truly needs a granite square, they need to know the the claimed grade and tolerances are reliable, else why the need for most accurate square you can get. Good luck with that with offshore stuff.

Something LIKE a Mitutoyo 972-109
Click to expand...

Have you called them? The squares are not hard to find - Starrett, Mitutoyo, Busch Precision and probably lots more have them in the catalogue. They are eye wateringly expensive, and frankly, not that much more accurate than you can make yourself by careful grinding or scraping (you can do that to better than a tenth, and a granite squares are 1/4 or 1/2 of a tenth, all over 6"). Or you could very to that spending a few hundred on a good Starrett or Mitutoyo machinist or bevel edged square

Can you tell what the use or need is? May there are alternatives.
 
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RobinHood

RobinHood

Ultra Member
Premium Member
Tom Kitta said:
This was supposed to be "apprentice" level thing - but its not as easy as it seems
Click to expand...
I agree 100%.

I made a cylinder square out of a hardened excavator bucket pin. Once you are down to < 1/2 thou, everything really matters. Left it sit overnight (because I was not done grinding), temperature changed by ~ 5*C in the shop. Next day the wheel was no longer making contact - it did the night before when I was doing spark-out passes. The part did not feel warm at all either - obviously it was a bit. After hours more grinding, the deviation is 3.5 tenths from largest to smallest diameter (as measured with a M & W 1/10 micrometer) and the base it nice and square to the side (does not really matter as you can always find the spot where it is - that’s the beauty of a cylinder square…).

The rough dimensions are 2.775“x 6.5”.
154E8C80-B5D3-4C8F-AD82-4325242280D4.jpeg
FF5F3560-9221-48D5-8B9F-07DA5373596F.jpeg
 
justindavidow

justindavidow

(Justin)
Mcgyver said:
I would be extremely cautious of anything except a recognized brand
Click to expand...

100% If I were looking to buy something with single-micron levels of precision on 4 sides and <0.0001 degrees-over-length out square for a job: 100%; I'd go to someone who runs the cal lab itself.

IN THIS CASE THOUGH; a square is easy to measure and like you mentioned: regrinding granite is very straightforward. Anything I buy is going to be "close enough" or can be adjusted easy enough.

Mcgyver said:
Have you called them?
Click to expand...

The major manufacturers that I know are not going to be interested in talking to me for a one-off. I'm coming from a hobbyist background and am looking to spend time on something, which simply isn't something their businesses are interested in.

Mcgyver said:
Can you tell what the use or need is
Click to expand...

A project in-and-of itself, and then something to use to measure and square built tools and products.

A cheap import would "do" for what I need; but my question was:

justindavidow said:
I'd really love to know if there are odd vendors that I should know about? Anyone come across a strange or unusual local (or at least Canadian?) vendor who produces squares?
Click to expand...

Honestly; I'd love to know if there's a granite importer that runs a hobby shop or something.

There are hundreds (or thousands!) of these people around; I just don't know who they are yet! :D
 
M

Mcgyver

Ultra Member
justindavidow said:
100% If I were looking to buy something with single-micron levels of precision on 4 sides and <0.0001 degrees-over-length out square for a job:
Click to expand...

A typical high end steel square with a cert you can rely on (say Starrett master precision square or Mitutoyo) will be within .0001" over 6" inches. A granite square is 1/2 or 1/4 that depending on the grade. It would be usually be considered as something for you need greater accuracy so if you couldn't rely on its grade certs, whats the point? At last that is the normal context of granite squares and what was behind my comment....none of which means you can't use one and be happy doing do...it just explains the context of my post. Still, what's it do for you if you don't know or can rely on its tolerances?

btw, my grinding comment was for orginated squareness with a grinder on steel. Granite stuff is lapped and imo isn't at all straightforward

The major manufacturers that I know are not going to be interested in talking to me for a one-off. I'm coming from a hobbyist background
Click to expand...
Sure they will. Starrett are fantastic, will talk to you and sell to you (at least thats my experience). Mitutoyo are a bit customer unfriendly, but they will still tell you where buy it and have a conversation about their items. Also, places like KBC will get you anything whether or not its in there catalogue. Mit only sells through distributors (grrrr) but if you call KBC they will get for you anything Mit makes. (something does not have to be in the KBC catalogue for them to source for you, hobby guys included)

A project in-and-of itself, and then something to use to measure and square built tools and products.
Click to expand...

There are ways to do this yourself - create squareness. I went through the precision stage, and its enjoyable and you learn a bunch However except for reconditioning and spindle making I don't find there is much need to go there in general shop work. One good square to .0001 that is only used for inspection should cover almost all the bases. Nevertheless, with nothing but a good plate and tenths indicator you can create squareness to better than a tenth over 6". Might be a good project if thats your interest and then you'll have a reference you can rely on.

A cheap import would "do" for what I need;
Click to expand...

I would say its not the price that matter so much as knowing and relying on the tolerances of each component; plate, square, etc. This is where the offshore items and precision often don't mix well if you can't rely on the the claimed flatness, squareness etc. In other words, imo, what any of us need for any given task as to know what the accuracy is a task requires and what the accuracy of the tool is....which of course can vary greatly from task to task

I feel like I'm probably coming across as argumentative; thats not the intent. I've just got a fair bit of experience with this and am trying explain how it works and so on. If you have specific applications, myself and many other skilled guys can give ideas on how to measure and check squareness
 
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