Square up a square?

[Dave Cottrell]

I have a try square with a wood handle and metal blade held in with 3 pins. It is about 1 or 2 degrees off. Is there a way to adjust these?

[Johnny Kleso]

Nope...

Most squares like these are just used on the inside corner, you can check to see if yours is OK..

David Charlesworth says he only used all metal squares (Hard Squares) for this reason and wood saquares often go out...

[Bill Houghton]

inside and out. If so, grab the stock (the "handle" part) and whack the beam (the metal part) on your bench, in the direction that will cause it to correct.

I know it sounds brutal, but I've got a Stanley all-steel square I corrected this way, and it's fine now.

As Mr. Kleso has mentioned, they're often designed only to be square on the inside - that is, for checking outside square, like testing that an edge is square to a face of a board. If the stock has brass edges, you can tell what the maker's intention was: the brass will be on the angle that the square was intended to check. If both inside and outside edges of the stock are brass-bound, it was intended to test both inside and outside square.

All-metal squares, such as engineer's squares, are often more reliable than even machinist-grade combination squares - though we're talking thousandths of an inch here, often irrelevant when working with a material that can move more than that between breakfast and lunch.

[Bob Smalser]

I have a try square with a wood handle and metal blade held in with 3 pins. It is about 1 or 2 degrees off. Is there a way to adjust these?

Sure, it's simple. All your squares should be checker periodically as even the most spendy go out of whack when dropped.

The standard way to test carpenter's squares is to find a surface with a clean, straight edge (such as a piece of plywood, or a machine table), put the square down on that surface with the short arm hooked over the edge. Draw a line along the inside face of the long arm (as if you were laying out a line perpendicular to the edge of the surface). Then flip the square over so that the short arm points the other direction and slide the square over and see if the inside edge of the long edge matches up with the line you drew. If it does not then the square is not square.

To true up framing or all-metal squares, you hammer a prick punch at the corner of the arms, the dimple you create moves the arms in the desired direction. Picture extruding metal at the corner opposite of the direction you want the upper or lower arm to move. Scribe a line between the inside and outside corners of where the arms intersect and confine your strikes to areas along that line.

To true up rosewood squares you hold one end in a vise, tap either arm true, then tighten the rivets by repeening lightly on an anvil or buck.

I prefer a ground tablesaw surface and it's miter gage dado for the checking function...and I check and adjust if necessary every single time they are dropped on the shop floor.

Simple enuf to do and there's no reason your Harbor Freight cheapo square can't be more accurate than the 200-dollar Starrett that is dropped and never checked....which is real common among rookie woodworkers who mistakenly strive for tool instead of operator accuracy. Over time, you can't buy your way out of tuning your tools.

[Wayne Cannon]

I don't trust the so-called engineer's squares, having seen too many of them that are not square. In fact, I've been surprised at how many squares of all kinds are not square, including name brands.

In addition to a Starrett combination square, I use a half-sized framing square that I adjust using Bob Smalser's "prick punch" technique, except that I use moderate taps with the round peen of a ball-peen hammer to expand the metal by dimpling it (at the inside or the outside of the corner, as appropriate).

I would be concerned that "whacking" a riveted square would loosen the joint and make it easier to again move out of square.

To test for square, lay it against a straight edge and mark a "right angle". Flip the square over along the straight edge and draw a second "right angle" line close to the first. If they are parallel, the square is square.

If a combination square needs adjusting, you gently file the ridge or dimple in the bottom of the slot, as needed (if it has one!).

[harry strasil]

I find that the cheap triangle squares made of either plastic or aluminum from any place, hdw store,discount store, etc are generally right on and don't get out of square due to the solid triangle construction.

Also, get a new bench square (mini version of a framins square) with a body of 12" and a tongue of 8" and make sure its square and only use it for checking your other squares. Put a daub of yellow paint on both sides somewhere so you won't pick it up by mistake and use it for ordinary work. Machinists call things that are used to check the accuracy of precision tools STANDARDS, so make your own standard.

[Bob Smalser]

I ain't talking about hitting anything hard to tighten a rivet. All you're trying to do is extrude enough metal in the rivet head to put pressure on the plate beneath it. In older rosewood squares that keep coming loose, you can add a rivet ( a simple brass pin peened on both ends) or even squirt some thin cyano in the joint.

[Dave Cottrell]

Adjusted and squared.

[Bill Houghton]

Over time, you can't buy your way out of tuning your tools.

Definitely my quote of the day. Thanks, Bob.

[ken seale]

Over time, you can't buy your way out of tuning your tools.


So very true!