https://www.lowbrowcustoms.com/lowbrow-customs-bolt-and-thread-gauge.html A must-have for any garage or workshop, this bolt size gauge is excellent for sizing bolts, screws, nuts (USS, SAE and Metric), washers (USS, SAE) and twist drills. A unique feature of this tool is that it has both US and Metric thread pitch injection-molded right into it! Simply hold up the threads of your bolt and quickly and accurately check the thread pitch (without having to go to the hardware store or trial-and-error