I own some precision measuring tools that are not at all necessary for woodworking but are superb for helping me diagnose problems and describe my world in my writing.
One of these tools is a Brown & Sharpe dial caliper, which I use mostly for examining tools and describing results in print (how thick a shaving can that plane take?).
The other tool is the Grizzly G9900 dial protractor, a marvelous tool for checking miters and bevels that have to be spot-on in complex work.
I have received a lot of questions about this tool since I demonstrated in at Woodworking in America last year and showed it during a short bit on The Highland Woodworker here. When you need to measure things to a fraction of a degree, this is your tool. It is accurate to 5 arcminutes. That’s pretty good.
Is this something every woodworker should have? No way. If you don’t deal in wacky angles, a combination square will do the trick.
But if you deal in work where you need to know angles that are in a fraction of a degree, I cannot think of any better tool for the price. I’ve owned mine for more than 10 years (back when it was about $30), and it has remained true.
— Christopher Schwarz