For quick shop work, the thread files are the best tool when it comes to counting or repairing external threads
by KEITH BERGLIND
Thread files are a handy dual-purpose tool around any repair job. They come in imperial and metric thread and are not very expensive. I keep one of each in each of my workshops. The most common tool source is the K-D tool display you see in many hardware and auto parts stores.
Of course, the main intent of a thread file is to file damaged external threads. That’s an easy and obvious job. Each square file has four different thread sections on each end, so one file will cover a wide range of eight thread pitches.