Another Mystery Item - Any Ideas on Use???

Hello, again. Another of my mystery items from a yard sale. This is clearly some kind of gauge or measure, but for what? It consists of 9 aluminium discs fastened together with a hinging rivet. Each has a square cut out of the middle in graduated sizes. The smallest measures 1" square; the largest 2.5" square. Each disc is marked with the size of the square. The largest square has chamfered corners. It bears no maker's marks, and could date anywhere from the 1920s to the 1970s. Has anyone got any idea what the purpose of this curious object might have been?? I'd be grateful if you could let me know so I can cross out another mystery. Thanks.

 

My first thought is a manual aperture for a specialized, large format, camera. There are many easier ways to measure size, so I'm thinking something to limit flow of light or liquid.

 

My only Idea would be some type of template plate for Mortising.

 

Would expect rectangles for that... unless you were building funiture for "This End Up"

 

I had that thought but I've never heard of a camera that has a square Aperture hole; since pretty much the beginning of photography the aperture holes have been located directly behind the lens and been circular.

 

That's why I said "some type", it was just a thought.

 

Square nut guide. (sort of like a drill size guide or nail size guide).

 

My first thought was that it was for "cropping" square format negatives for printing things. The film is or was 2x2 inches per neg or thereabouts, and back in the day you'd have used a physical mask to crop your image. Then you'd put it into the negative carrier and slide it into the enlarger.

 

Either my father or my grandfather had one of these, therefore, it would have had to do with the construction of...something.

I have no idea how Coreya's "square nut guide" works, but I think I am picturing something like a washer...the ones in the sink...

no very helpful, but at least I have Seen the thing!

 

I'll link this thread over to "Practical Machinist" forum where they should know even if it isn't a machinist tool.

 

Thanks for the help so far - all good stuff. I'm doubtful about the photo aperture idea because the quality just doesn't feel right for a technical photography use, although I wouldn't rule out the cropping idea. I think more likely some kind of mechanical use - so some kind of guide or gauge. Maybe something will come from practical machinist side. Is it too big for a square nut guide?

 

On the other forum, Lester Bowman wrote: "...I would immediately say it's just a pocket gage for measuring different sizes of square steel tubing. The design suggests itself for that purpose..even to the detail of have the radii cut into the larger corners. A convenient pocket tool used in steel sales to quickly gage steel tubing stock to avoid mistakes. Isn't that obvious?"

Lester, thanks, but to answer your question, no, it isn't obvious.

 

ya maybe a tubing gauge . i will ask darwin he's a pipeline welder i worked with , he will know, he's a metal/plastic tool know it all lol

 

Well Lester, a square tube is the same on all sides, so your pocket rule would suffice for measuring its size. But it could be an asset for round stock measuring.

 

It would be less bulky than a tape measure or ruler in your pocket but it seems cumbersome to use for measuring.

 

We find these around here, but with round holes, in exactly the same sizes. Ours are fruit gauges or sizers for sorting and grading fruit. This area has a very long orchard tradition.

Not saying that's what this thing is, though. Putting round fruit in a square hole seems a little odd.

 

Thanks so much for putting it on the other forum. This does sound about right - it would seem likely to be a pocket tool, and measuring tubing seems a very likely use. But as you say, no it wasn't obvious! Thanks again!

 

Hello - it would be great if you could ask him - just to confirm. Thanks

 

Hello - someone else I know suggested this was a gauge for measuring potatoes - but same as you, I thought it was strange that the openings were square! Its interesting that you use similar tools though.

 

Heck, they make something similar for figuring out how much spaghetti to cook for dinner.(LOL)