Use a Steel Square As a Try Square





Introduction: Use a Steel Square As a Try Square

About: I miss the days when magazines like Popular Mechanics had all sorts of DIY projects for making and repairing just about everything. I am enjoying posting things I have learned and done since I got my first ...

I like using a Try Square.  Sometimes I wish my small steel square could function as a try square, too.  With the piece of wood shown in the photo, that is easily done.

Step 1: Begin With a Piece of Wood

Begin with a piece of wood 3/4 inch thick and nearly as long as the longest leg on your steel square.  Make it a bit wider than the longest leg of the steel square is wide.  Make certain the edges on the long sides of the wood are truly parallel to each other.  One way to insure this would be to run the piece of wood between a fence on a router table and a straight bit in the router.

Step 2: Make a Kerf

Make a kerf about the thickness of the steel square.  If the kerf is made to fit snugly, the piece of wood will stay on the square by itself.  Make certain the bottom of the kerf is parallel to the edges of the piece of wood.  This should be no problem if the kerf is cut on a table saw.

Step 3: Half-circle Opening

I used a hole saw to make a half-circle cutaway in the piece of wood.  It should be located so you can apply pressure to the shorter leg of the steel square, in case you are using the longer leg to mark something. 

For the setup I clamped another piece of wood next to the edge of the wood with the kerf.  This supports the hole saw more completely while cutting.

Step 4: Kerf Across the End

For an extra touch I also made a kerf across one end of the piece wood so the square slides down into it.

Step 5: Use the Square

Here I have slipped the piece of wood over my steel square's shorter leg.  My finger applies pressure against the shorter leg to keep it firmly pressed against the piece of wood I made and also against the edge of the piece I am marking.  If the kerf is a little loose, a couple of small pieces of paper could be folded a few times and the folded paper could be slipped into the kerf with the leg of the square to function as a wedge that helps to hold the square in the wood. 

The second photo shows using the square to mark with the shorter leg.  Because the longer leg of the square is wider than the kerf in the wood is deep, my fingers can press the square against the wood at any point along the leg's length.



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    Phil, cool idea. The converter can hide in your tool box until u need it for a cross cut.
    if you drill the hole first in a wider board - less chipping, easier to hold it - you can then rip the board and proceed with the rest of your neat design, making 2 converters at once.

    1 reply

    Thank you for a good idea. I shared the basic idea with a man who had only a couple of flat steel squares, but sounded as if he would not mind having a try square. He planned to go home and try it. I have not talked to him since to know how it worked out for him.

    very simple, very clever
    ill try it tomorrow if its not too hot.

    1 reply

    Thank you. I apologize for missing your comment until now.

    While a LOT of people mis-spell it, the actual name of this piece of equipment is a TRI square.

    There're enough who spell it wrong that you can easily google a "try square" and find out what a tri square is... and probably not be told you spelled it wrong. But check a dictionary or other similar reference source; tri square is the proper spelling.

    5 replies

    You may also let the know at Merriam Webster know that they too misspelled "Try Square". Also ask them to include the new contraction "There're"  I searched the online dictionary for both "Tri square" and "There're" and both resulted with "not found"

    THis "tri-cornered" argument is "trying" my patience.

    After questions about spelling (Tri or Try) arose, I was in a national chain home improvement store.  Their squares offered for sale are all made by Swanson, who spells it Try Square.  

    Actually, it is correctly a TRY square. Similar to a TRY plane (a/k/a trying plane or fore plane). This comes from an earlier form of English than most of us practice these days. When using this instrument , it was said that the workman was "trying" the work - i.e., checking the work to see if it was square. Thus, this tool is a square for trying the squareness of the work - a try square. A trying plane is for trying a piece of work to assure its flatness.

    I checked the spelling through a web search and was led to the "This Old House" web site.  They gave the spelling at "try" square.  I could not remember for certain, and accepted their spelling.  Thank you for the correction.

    Nice little adapter. I might have to make myself one as the tri-square I have is often too small. It might be a good idea to check it for square too (both with and without the adapter). It's easy enough to draw a line, flip the square and check that the line is still parallel to the square.

    1 reply

    Good points.  It is good to check the square, particularly with the adapter in place.  At times it is nice to have a larger size tri-square, and this accomplishes that without buying another square. 

    Some time back I did an Instructable on making certain your square is truly square.

    The tri-square in the Introduction belonged to my father.  I am passing it to my daughter.  I had promised her a "T"-bevel square that had also belonged to her grandfather, but I think I already gave that to my son.  I will still want a tri-square now and then and will use my little adapter.

    Thank you for your comment.

    Thank you, my friend.

     It's clever, but why not just rest the inside of the steel square against the wood being measured? That way you don't add two more surfaces to increase the inaccuracy. Not only does the kerf need to be straight and parallel to the back of the wood, but the back of the wood must be kept straight and "undinged" as well.

    1 reply

    What you suggest is what I have done over the years.  It works much of the time.  But, there are times when there is rounding at the corner edge and the square tends to slip, or when I need the square to be flat on the top surface of the work, not angled slightly off of the top surface. 

    Yes, a person does need to choose the piece of wood used for what I did here with care so the wood is "ding free."

    You don't stop with these handy tricks, so simple, but rather clever too.


    1 reply

    Thank you.  It just came while I was thinking about other things.