Square

Incra GSQR7 Guaranteed Square 7-Inch Precision Square
$49.95
Most people who buy a precision square do not have any means of checking to see if it is precise as the manufacturer claims. So, we have to rely on the reputation of the manufacturer and on the recommendations and critiques of others. Before I ordered the GSQR7, I read the reviews here on Amazon. I was persuaded that it was an excellent product (although I had not previously heard of Incra). So, I ordered it.

It arrived very quickly via the free shipping.

Right out of the box I was a little surprised to find scratches on the square. I concluded that these were probably the places where the electrodes were attached during the anodizing. The next realization was that, despite the prominent claim of the manufacturer that this is a "one piece design", it certainly is not. I counted 12 pieces in all (including 4 bolts, 4 nuts and a decal) and I can't imagine anybody honestly describing it as having fewer than 3 pieces - the main "L", and the two red handle pieces. Certainly this would be less expensive to manufacture than a one piece design, but it's not what I thought I was buying.

I also noted that there is a threaded hole in the blade of mine, which is not shown in any of the photos on the product package nor in the photos shown here on Amazon.

The manufacturer has made two claims
1) It's a one piece design.
2) The blade is accurate to within 1/1000 of an inch throughout.

The first claim is clearly untrue. I don't have any easy way to verify the 2nd claim.

The product did not come with any documentation other than a little card which says "Certificate of Accuracy : Incra guarantees the accuracy of this precision instrument to conform to all manufacturer's specifications. Angular accuracy is guaranteed to be less than 0.001" maximum deviation from nominal at any point along the full length of the blade."

However, no "manufacturer's specifications" were supplied with the product. Also, it is interesting that they specify that only the "blade" is accurate, not the handle - and yet the handle is flush with the blade on the lower side (so that inaccuracy of the handle will affect the results in actual use) and one illustration on the box demonstrates the product being used in a configuration which relies on the accuracy of both the upper surface of the handle and the blade.

So, I'm disappointed. Perhaps everything is just great. Perhaps the handle is just as accurate as the blade. Perhaps the entire unit is square on every surface to the specified 0.001". I simply don't know.

If Incra is going to make a precision instrument, then they need to make precise statements about it.

Swanson Tool SO107 12-Inch Speed Square
$25.20
I would pay double for this square. I use it and it's smaller 7 inch cousin every single time I have a project. The thing that sets it apart from other squares is that the base has a lip on it that you can set on your project to square up perfectly. Another plus is that you won't worry about scratching it up since it has a brushed aluminum/industrial kind of finish on it.

I use it as a marking guide, square, and straight edge for my jigsaw/circular saw.

Used in concert with my 18inch Incra T-Rule I'm the master of measuring/marking.

CH Hanson 34512 A-Square 3 x 4 x 5 Folding Layout Triangle Package
$57.99
I was not impressed with the flimsy design of this square. I does seem to be accurate, but I am unsure how long it will stay that way with repeated use.

Stanley 45-300 Aluminum Carpenters Square
$15.49
Does what it's supposed to do. Arrived square and still is to this day. I think it's a must for any DIY inventory.