How to "restore" machinist square?

[Doug Hobkirk]

These came from a garage clean-out - there were a lot of old tools. I think these are called machinist squares. The blades of two are quite square compared to a new Grizzly steel square (the small brass square is slightly splayed). The inside blade on all 3 does not have a perfect straight edge.

I imagine they are not valuable and I could restore using abrasives, but sometimes it is smart to ask first. The steel handle square is imprinted with Stanley on the blade. The handle of the large brass edged square is imprinted with "Henry DistonXX" (I cannot read the last letters), "PHILDA.", and "NO1."

I have given each a quick rub with a piece of fine-grained gray mesh and wiped them with a little Fantastic. There was very little difference.

ALSO, as an aside, is there any good use for old hand saws other than cutting them up to make scrapers? One of the two dozen saws from the garage was imprinted with (approximately - I am going from memory) "Made for the Normal Training School in Philadelphia by Diston." I volunteer at a household goods recycling organization and we get quite a few saws, both conventional carpenter saws and smaller dovetail style (?) saws, almost all of which are put in the trash. The saws are almost never sharp.

Thanks all.

[Rob Young]

I believe these are Try-squares, just happen to have metal blades and some brass wear plates.

Unless the brass pins are removable, they aren't adjustable except by filing the blade.

Given that the last one is stamped Henry Disston and has a model number, you should be able to find out lots more information on that particular piece.

[David Gendron]

Good day, the square you are showing, look to me to be try square used for wood working. the one marked Disston #1 is the same make as the well known saw maker Disston and son! As for all the saws you are talking about, I'm sure some of them could be great users, look for tote that are in good shape and a blade that doesn't have rusting pits or at least not close to the tooth line. you could show picture and we would be able to tell you what they are and you could even get money for them if you are not a user of hand saws!

[Jim Koepke]

Try squares, as others have said, is what these are called.

My suggestion is to very carefully use a file to "adjust" the blades.

Some do suggest using force, but that may introduce the possibility of play in to the blade.

Testing is best done by holding against the side of a straight surface and scribing a line. Then flip the scale over and scribe another line. If the lines are parallel, the square is good. If using a pencil, make sure it is real sharp and maybe a bit harder than the standard #2. A pencil will allow the use of paper on a table with a true edge. A marking knife is good on a piece of wood.

My accumulation of tools includes an inspector's loop with a piece of glass scribed with measuring devices. (a quick search indicates the proper nomenclature is reticle) to detect variations as small as .002". These are useful for such work.

Search for reticle loop, eyepiece or magnifier and you will find things like this:

http://measuringmagnifier.com/

There are many types for different uses.

jim

[Chris Vandiver]

There are collectors(and users)of Manual Training School saws, so there is a market for them.

Chris

[mike holden]

Doug,
Rather than throwing out the saws, try putting them on the bay to generate funds for the recycling center. All orgs can use money.

Or.....You could send them to me, and I will dispose of them. (grin)

Seriously though, older saws can be sharpened and used. The ones with hardened teeth can be recycled into scrapers, scratch stocks, etc.

Mike

[Bill Houghton]

One point: traditionally, the only edge that was considered reliable on a brass-bound try square was one with the brass binding. Thus, the Disston square pictured, for instance, would be OK for testing external square, but not internal. A few try squares were brass=bound inside and out, and usable for both inside and outside testing.