Bridge City ToolWorks Combination Square - Is it as accurate as they claim?

Bridge City claims an accuracy of +/- 0.002 inches for their combination squares. I bought a 6 inch one to see what they are all about, and to test that claim. The video gives my initial reactions about the square and a test of its accuracy. I also compare its accuracy to my other 6 inch combination squares, including the Starrett discussed in an earlier video which I have now improved a factor of 2.5 with about an hour of hand work.

The accuracy was tested by measuring the squareness 5 times at each of 4 configurations for each square. That is, the configurations were cycled through 5 times to produce the data. The result plot shown in the video depicts the means and standard deviations of the 5 determinations.

[ozyrob]

I just happened onto your channel. I noticed you've only made 4 videos but 2 new ones very recently. Nice content and advice. I hope you make more. Thank for doing this.

[melgross]

I have one of theirs for woodworking. It’s more comp, exchange this one is. It’s very well made and quite precise. I measured it in my machine shop. The point of my post though is that it’s engraved with laser. Did you check? Laser engraving looks different from either mechanical or chemical engraving.

I’d like to say that I never rely on these types of squares for anything other than a rough guide. My mill will square off the parts I’m working on. If I really need to mark off a parallel line I use my granite and a height qauge with scriber tip. The granite plate is indeed flat.

[airnashville]

Like your previous comment, I ran across this by accident. I know the guy who started BCTW; John Economaki. He's still involved but, it's entirely an import company. They specialize in "bling" for the woodworker. Their tools are a horrible value for the money and are made to sit on the wall an be pretty.