Accurate Triangle metal square

[michael101]

Hello friends 

im looking for an accurate drafting triangle square in size of 12’’ [30cm] 90 degrees made of metal 

but in each one when I’m looking at the reviews over the internet the said it’s not accurate …

can someone recommend about a very accurate one?

best regards,

Michael.

 

[Bob Cleek]

The Theodore Alteneder and Sons drafting instrument company made stainless steel drafting triangles years ago. They came in various sizes. Alteneder made some of he highest quality drafting instruments in their day.  https://www.worthpoint.com/worthopedia/drafting-triangle-with-handle-theo-alteneder  You'll have to track the eBay "drafting instruments" offerings for a while before you come across one these days. (In the last few years, high quality manual drafting instruments have become very collectible and can be surprisingly expensive, although there are still a few bargains to be found by the knowledgeable buyer.) Metal triangles can also be sometimes found on eBay in the machinist's tools section.

 

I'm somewhat confused by your report of accuracy problems on internet reviews. It's not rocket science to produce a 12" 90 degree triangle out of sheet metal. I'd expect most sheet metal shops worth their salt would be able to turn one out for you in a few minutes. What kind of accuracy are you talking about? A Starrett or Brown and Sharpe (these are identical products) draftsman's protractor is accurate to five minutes of arc. (It was Starrett's catalog item No. 362.) This is the instrument that would have been used by a draftsman who wanted the most accurate instrument available. They were frequently used to replace triangles. They come up on eBay with some frequency, or used to. They sold for $75 bucks in the 1960's. A mint example in a good condition velvet lined fitted case may now set you back $100+, but who knows on any given day on eBay. It's a lovely instrument with classic Starrett aand Brown and Sharpe "finestkind" quality.

 

 

[mtaylor]

Does it have to be metal?  There's still very accurate plastic ones available.

[michael101]

8 hours ago, Bob Cleek said:

The Theodore Alteneder and Sons drafting instrument company made stainless steel drafting triangles years ago. They came in various sizes. Alteneder made some of he highest quality drafting instruments in their day.  https://www.worthpoint.com/worthopedia/drafting-triangle-with-handle-theo-alteneder  You'll have to track the eBay "drafting instruments" offerings for a while before you come across one these days. (In the last few years, high quality manual drafting instruments have become very collectible and can be surprisingly expensive, although there are still a few bargains to be found by the knowledgeable buyer.) Metal triangles can also be sometimes found on eBay in the machinist's tools section.

 

I'm somewhat confused by your report of accuracy problems on internet reviews. It's not rocket science to produce a 12" 90 degree triangle out of sheet metal. I'd expect most sheet metal shops worth their salt would be able to turn one out for you in a few minutes. What kind of accuracy are you talking about? A Starrett or Brown and Sharpe (these are identical products) draftsman's protractor is accurate to five minutes of arc. (It was Starrett's catalog item No. 362.) This is the instrument that would have been used by a draftsman who wanted the most accurate instrument available. They were frequently used to replace triangles. They come up on eBay with some frequency, or used to. They sold for $75 bucks in the 1960's. A mint example in a good condition velvet lined fitted case may now set you back $100+, but who knows on any given day on eBay. It's a lovely instrument with classic Starrett aand Brown and Sharpe "finestkind" quality.

 

 

Thank you ! 

i need it to be a perfect straight without any bend and also to be a perfect 90 degrees 

for caliber my proxxon machines like a table saw scroll saw disc sand act.. so your beautiful tool cant help with that because it not has a sharp corner

but thank you anyway ! 

 

[michael101]

7 hours ago, mtaylor said:

Does it have to be metal?  There's still very accurate plastic ones available.

i have a few and im used them at the moment but like you know you can easily scratch the edge then you loosing the calibration..

 

[Jaager]

10 minutes ago, michael101 said:

to be a perfect straight without any bend and also to be a perfect 90 degrees 

for caliber my proxxon machines like a table saw scroll saw disc sand act.. so your beautiful tool cant help with that because it not has a sharp corner

A machinist square?

[michael101]

I have found this tool who got a beautiful reviews about the calibration !!!!

here is the reviews:

https://www.amazon.com/product-reviews/B073YGVQT3/ref=cm_cr_unknown?ie=UTF8&filterByStar=five_star&reviewerType=all_reviews&pageNumber=1#reviews-filter-bar

and there is also a store how sale that in Europa:

https://shop.kinexmeasuring.com/en/precision-triangle-kinex-250mm-45-90-csn-25-5162-csn-25-5163-p9002369c22c189/

you can also get with it CALIBRATION PROTOCOL

now im wasting to the sore so send me the shipping cost ..

----

but again if someone still can recommend other tool i will be happy to hear

Best regards

Michael.

[michael101]

7 minutes ago, Jaager said:

A machinist square?

yes ! i think the drafting one can do a perfect job for that .. correct me if im wrong 

[Bob Cleek]

4 hours ago, michael101 said:

Thank you ! 

i need it to be a perfect straight without any bend and also to be a perfect 90 degrees 

for caliber my proxxon machines like a table saw scroll saw disc sand act.. so your beautiful tool cant help with that because it not has a sharp corner

but thank you anyway ! 

 

If I understand correctly what you want to use it for, the proper tool for that job is a machinist's square. The come in many different sizes and prices, but are all perfectly accurate, or should be, unless you drop them. The beam (wide leg) is designed to lay on the flat surface, such as a saw table, and the blade is designed to stand perfectly normal (at a right angle) to the flat surface. 

 

 

https://www.grizzly.com/products/Grizzly-4-pc-Machinist-s-Square-Set/H2993?iparcelcountry=US&msclkid=41db45718134178ed1d01a2934507070&utm_source=bing&utm_medium=cpc&utm_campaign=%5BADL%5D%20%5BPLA%5D%20%5BShopping%5D%20-%20%7BGeneric%7D%20-%20Desktop&utm_term=4585925561291301&utm_content=%7BGeneric%7D&adlclid=ADL-5c1f93f0-705f-4049-88ab-150c3be7bf86

 

[michael101]

20 hours ago, Bob Cleek said:

If I understand correctly what you want to use it for, the proper tool for that job is a machinist's square. The come in many different sizes and prices, but are all perfectly accurate, or should be, unless you drop them. The beam (wide leg) is designed to lay on the flat surface, such as a saw table, and the blade is designed to stand perfectly normal (at a right angle) to the flat surface. 

 

 

https://www.grizzly.com/products/Grizzly-4-pc-Machinist-s-Square-Set/H2993?iparcelcountry=US&msclkid=41db45718134178ed1d01a2934507070&utm_source=bing&utm_medium=cpc&utm_campaign=[ADL] [PLA] [Shopping] - {Generic} - Desktop&utm_term=4585925561291301&utm_content={Generic}&adlclid=ADL-5c1f93f0-705f-4049-88ab-150c3be7bf86

 

Thank you , 

i prefer the flat ones but like i wrote before i dont know why but there is a lot of bad comments in AMAZON about different company who making this ruler 

im still keeping searching for a good one 

so if someone hear has a accurate one i will be more than happy to know hat company is it..

[Bob Cleek]

I'd be curious to see the bad reviews on Amazon. I've been using squares for sixty years or so now and in all that time I've never seen or heard of anyone complaining about a commercially made square of any material being out of square or otherwise "inaccurate." (The rivets in a machinist's square can sometimes be loosened and the blade be out of true if the square has been dropped, but that's another matter entirely.) 

[bruce d]

19 minutes ago, Bob Cleek said:

never seen or heard of anyone complaining about a commercially made square of any material being out of square or otherwise "inaccurate."

Hello Bob. I have had a ground steel 200mm engineers square that was out by a whole degree: it happens. Fortunately, that amount of 'slop' doesn't happen very often but it is wise to check carefully especially if buying budget tools.

 

[Bob Cleek]

26 minutes ago, bruce d said:

Hello Bob. I have had a ground steel 200mm engineers square that was out by a whole degree: it happens. Fortunately, that amount of 'slop' doesn't happen very often but it is wise to check carefully especially if buying budget tools.

 

In this day and age of CNC manufacturing, I'm amazed! It's easy enough to check the accuracy of a square by laying it on a T-square or other straight edge and drawing a perpendicular line, then flipping the square over and lining up the edge with the perpendicular line. If the edge perfectly aligns with the drawn perpendicular line, it's accurate. Darn it! Now your report is going to get me checking all my squares as I have occasion to use each of them, just to make sure their true!  

[RichardG]

1 hour ago, Bob Cleek said:

I'd be curious to see the bad reviews on Amazon. I've been using squares for sixty years or so now and in all that time I've never seen or heard of anyone complaining about a commercially made square of any material being out of square or otherwise "inaccurate." (The rivets in a machinist's square can sometimes be loosened and the blade be out of true if the square has been dropped, but that's another matter entirely.) 

I returned a steel center finder from Amazon recently. It was definitely off. The item was cheap and I wasn't too surprised. The Amazon reviews were mostly good with a few "1's". Lot's of people saying the bad reviews were because they didn't know how to use it. I suspect it was bad quality control. 

[mnl]

If you want something serious, consider a granite square, something like this:

 

https://www.penntoolco.com/precise-15-x-10-x-1-5-precision-granite-square-303-177/

 

good for 0.0001”/6”

[Nirvana]

I clicked on the link and got the sale pop-up on their website.

Calipers of high grade!

[wefalck]

If I understood correctly, you are not actually lloking for a highly accurate triangle/engineer's square, but rather a way to set cutting tools (e.g. saw blade, sanding disk, etc.) square to the table with sufficient accuracy. It would be helpful to think about how much accuracy you actually need. Something with test certificates seems to be completely over the top for setting woodworking tools. In normal workshop practice standard engineer's square should be perfectly adequate. Their squareness is easily qualitatively tested as described by someone above.

[Wilf13]

I'm very late to this conversation, but for what its worth, I can personally attest to having used a Kinex 250mm 90 & 45 degree triangle to set the blade and the cross-cut fence for the table saw in my pro furniture-making workshop in the UK for the last 4 years or so. If anything, the square has shown up certain limitations in the fence!

[jud]

Want a right angle? Don't forget the 3, 4, 5 triangle. Using that method you can obtain a right angle of any size within the precision of your measuring tools and your ability to use them. Lots of Data on the net, I have used the method many times on paper, wood and ground, it maters not what linier units you choose to use. Mark your corner, lay a base line out and mark as precisely as you can 4 units from the corner, from that point measure 5 units and scribe an arc near where you expect the corner to be, return to the corner and make another arc at 3 units from the corner, the intersection of the two arcs is the final corner of your 90°, 3, 4, 5 triangle    

[Bob Cleek]

[Nirvana]

How did the Pie turn out? 

[Nirvana]

20 hours ago, jud said:

Want a right angle? Don't forget the 3, 4, 5 triangle. Using that method you can obtain a right angle of any size within the precision of your measuring tools and your ability to use them. Lots of Data on the net, I have used the method many times on paper, wood and ground, it maters not what linier units you choose to use. Mark your corner, lay a base line out and mark as precisely as you can 4 units from the corner, from that point measure 5 units and scribe an arc near where you expect the corner to be, return to the corner and make another arc at 3 units from the corner, the intersection of the two arcs is the final corner of your 90°, 3, 4, 5 triangle    

Old classic working method, and always right!

[KeithAug]

On 11/1/2022 at 2:06 AM, Nirvana said:

How did the Pie turn out?

It was easy, she just flipped over the pan.

[Bob Cleek]

23 hours ago, KeithAug said:

It was easy, she just flipped over the pan.

It was at that point that she discovered it was a casserole, not a pie. What can i say, it looked like a pie to me when I took it out of the freezer! So I said, "Don't blame me. Who bakes a pie at 120 degrees anyway?' And it went downhill from there...  

Edited November 4, 2022 by Bob Cleek

[KeithAug]

1 hour ago, Bob Cleek said:

And it went downhill from there... 

Hmmmm! Best not to upset the admiral.

[Bob Cleek]

52 minutes ago, KeithAug said:

Hmmmm! Best not to upset the admiral.

Most decidely!