Originally Posted by
Stan Stocker
Greetings! Look up three wire thread measurement. With a micrometer, a bit of clay or a sense of humor to juggle/control three wires, and a couple of tables you can measure most threads. PeeDee sells a low cost set of thread measuring wires. For one off, you can buy a cheap large assortment of sewing needles and measure out several sets of three to cover most common smaller threads. Old school, not sexy like super precision thread measuring micrometers and the like, but works just fine. It's a step up from testing with off the shelf hardware, and sufficient for many folks who only have occasional need to do better that "does it fit the nut?" thread cutting.