Easily measure tough diameters with this simple combination square trick.
Measuring diameters can be difficult. Sure, it works OK to just measure the end, but if you need accuracy, here’s my method. Take apart one of your combination squares and slide the head to another square so that the straight edges are facing each other. Set one of the square heads at an even measurement and then slide the other head until both are touching the part you’re measuring. Read the measurement right off the ruler!