As late as 1972, I bought a number of Union Tool Company combination squares for a powerplant construction project I was working on. I told the supply firm to give me some "good combination squares with protractor heads- but NOT at the price of Starrett..." I gave these squares out to the pipefitters, who used them to lay out cuts on steel angle and similar to make pipe supports, and to determine angles for some mitre cut bends on pipe. These squares "were expendable" and wound up with weld spatter and nicks and rust as use on a jobsite by pipefitters putting in welded piping and fabricating supports is hardly machine shop or toolroom work.
The lack of quality when compared to a Starrett or Brown-and-Sharpe combination square is evident. I use my Starrett combination squares for machinist's work in my shop.
have one of the Union Tool combination squares in my own tools, ever since 1972. It is my "knock around" combination square and winds up in a bucket with my welding and fabrication tools when I do welded fabrication work. I find that the graduations on the Union Tool Company square are hard to read, even when polished with "Scotchbrite", and the "feel" of the square is not quite up to Starrett. I have no problems in using that square to layout work using soapstone lines, and having it around welding, grinding, oxyacetylene cutting, and similar.
Who knows what happened to Union Tool ? Orange, MA is next to Athol, MA- the home of L.S. Starrett. It is also not far from the homes of Greenfield (taps and dies) and Millers Falls, and Goodell-Pratt. Chances are people worked at these firms and jumped ship when the getting was good at one of the other firms in the region, so design was pretty generic. How many ways can you make a combination square or pair of spring dividers ?
New England was the "cradle of precision manufacturing" in the USA, and that part of New England was loaded with firms making all sorts of products such as firearms, sewing machines, bicycles, precision tools, and machine tools and much more. Orange Tool was one of the last of them, with only Starrett surviving.
My own personal preference for dividers is the kind which have the square "legs" and the screw passes thru a hole in the legs. Much neater design than the kind which have the screw set in steel pivots that are staked into flat legs. I have plenty of dividers and calipers, some of the more modern "flat leg" style, some of the older "square leg" or "round leg" style. I never thought of any of these as "collectable" and just use them in my work without thinking twice about it.
Of all the machinist tools, probably the ones where the manufacturers' names matter the least are the spring dividers and calipers. These are for more of "comparative" measurements, and not in the class of micrometers or vernier calipers. Nice to think of collecting these types of tools, but hardly what I'd consider anything special.
It is not like coming in with one of Starrett's first combination squares, or a Parker shotgun (made by the same Parker who made the fine machinist vises in Meriden, Connecticut). Somewhere in tools I got from my father, I have a screwdriver bit with a shank to fit in the chuck of a hand brace. What makes this screwdriver bit unique is it has the scripted "Winchester" logo on it. Winchester- the firearms maker- apparently made hand tools to carry them along when firearms sales were not where they needed to be. Stevens- best known as a firearms maker in Chicopee, MA- made a line of spring bow calipers. These are the sort of thing I could get mildly interested in. Orange Tool- pardon my saying so- is "nothing special", and Starrett spring calipers and dividers are the proverbial "dime a dozen". Calipers and dividers made by machinists or toolmakers for their own use are the thing, in my opinion, to be looking for. Stuff with the color casehardening, "rope knurling", and the fine one-off workmanship. THAT gets my interest and appreciation as an old time engineer and machinist.
