Replies

1. 
   Brian_Hinther | Jun 10, 2010 10:18pm | #1

   Here are some options from Lee Valley:

   http://www.leevalley.com/us/wood/page.aspx?p=32600&cat=1,42936

   They have some better ones, but they aren't graduated.

2. 
   Routerman | Jun 11, 2010 09:53am | #2

   Square inside & out but not

   Square inside & out but not graduated.

   http://patwarner.com/try_square.html

3. 
   HowardAcheson | Jun 11, 2010 10:54am | #3

   Here is some info that may be helpful.

   No matter how much you spend for a device, you still don't know if it is square. I ran a large tool and die shop and we purchased a number of Brown & Sharp and Starrett devices and some of them were not "square". We had "standards" that our quality department periodically had validated by an outside service that we then used to verify the worker's tools.  One day, one of our designers brought in two plastic drawing triangles he had purchased at a local art supply store. He had them compared to our standards and they were as accurate as the tools could measure. The triangle cost a couple of dollars each. They would certainly serve very well as the "standard" in any woodworking shop to validate and/or adjust other devices.

   An excellent way to validate the accuracy of the plastic squares is to use two squares on a flat surface.  Get a $10-12 plastic 30-60-90 drafting square. To prove it's exactly 90°, take two to a glass counter, put the shorter legs on the counter and face the longer legs away from each other and butt them together (like a teepee). If the legs exactly butt, you can assume you have two perfect 90° angles. Using one of the plastic squares, do the same thing using your other tools. Any that mismatch, means that the tool is not square. You can also take the plastic square with you whenever you go to purchase another tool. Keep your "standard" somewhere where it doesn't get banged up.

   Finally, remember that the wood you are using will expand and contract a couple of thousands from one day to the other. Does't pay to get too uptight.

   While we are at it, I also only purchase the cheapest of adjustable squares. I square them with a drafting triangle and an auger file until they are square across 10". And I own a Bridge City square that isn't that accurate. Stainless steel machinist's squares are only square until you drop them. I have had several over the years and each has found a away to drop to the floor.

   The key is to NEVER use your best square on for day to day measuring.  Use it only as a reference tool to verify your other day to day tools.

   In a comparison test reported in Fine Woodworking Magazine a couple of years ago, the Stanley 46-123 square was awarded the best value.  It's much less expensive than a Starrett and just as accurate.

1. 
   JohnWW | Jun 11, 2010 03:39pm | #5

   Glass is not flat

   There is no reason to expect that a glass countertop is flat enough to be used as a reference surface.  Is moderately flexible and will easily sag under its own weight.

1. 
   HowardAcheson | Jun 11, 2010 05:20pm | #6

   John, as I said in my write-up, the triangles were tested under machine shop conditions.  Certified granite surface plates were used as well as certified measuring comparitors.  Our shop made plastic injection molds for making parts for various electronic and computer manufacturers.  It was an ISO certified shop.

   While I agree that glass countertops can be somewhat less than perfectly flat, I will argue that they are flat enough for the purpose I suggested.  After all, these tools and measuring devices are being used for woodworking and the degree of accuracy in the process I describe is more than accurate enough.

1. 
   whitedogstr8leg | Jun 12, 2010 12:29am | #7

   Try square

   I was taught a way to check a square for "square' was to use a board with a straight edge.   Lay the square on the board and draw a line.  Next, flip the square over and make a second line right over the first line.   Square is square IF there is one line all the way to the end of the line.    If not, then that square needs a little work.   Which way the "V" goes will tell which way the square is off.   Good evening, Howie.   Good to see you again.

2. 
   JohnWW | Jun 19, 2010 09:48am | #11

   My experience is that ordinary plate glass is not flat enough even for modest woodworking levels of accuracy and that plate will easily sag to match the contours of the surface it is sitting on or will sag if only supported around the plate's edges.

4. 
   wotnow | Jun 11, 2010 02:27pm | #4

   Adjustable "Square" Square.

   Quickstep

   Have a quick Google for a Sweedish NOBEX OCTO square. I'm sure they are available in the US. It is adjustable through 8 preset (the standard culprits) angles  by clicking it through pre drilled holes in the blade and being registered at the angle by spring loaded ball bearings. It is incredibly accurate, I have had one for years and not had a problem with it. It has a guaranteed tolerence of +/- 0.05 degrees and comes in sizes of 8", 12" and 18".

   wot

5. 
   jg0258 | Jun 12, 2010 09:08am | #8

   Why not make your own? Chris Schwars had a blog on making your own try square on the PWW blog. I would give you a link but I find the PWW web site impossible to navigate. Anyhow, the idea is you make one from wood. Why a drafting square you can check it for squareness and it cannot get any cheaper than this. This is what I plan to do for my next try square.

6. 
   Jfrostjr | Jun 12, 2010 11:17am | #9

   Squares

    "And I own a Bridge City square "

   It may not be accurate - but it sure is pretty.

   Frosty - I've always lusted about their tools but never popped for one.

7. 
   RalphBarker | Jun 18, 2010 10:49am | #10

   nomenclature

   Now that various good alternatives have been suggested, I'll pose the question: why is a try square called a try square?

   If we follow the wise advice of Master Yoda ("Don't try. Do."), and the square is accurate, shouldn't it be called a do square?  ;-)

8. 
   Quickstep | Jun 19, 2010 11:46am | #12

   I think it should be called a "do" square if your cuts are accurate. I always assumed the name came from using it after the cut to "try" to see if the cut was square.