Yes, I have thread files, six of them, imperial and metric, and use them as needed; there is another device made by "Buckingham, of Binghamton, N.Y." that has a rectangular housing with a hole through its thinner dimension containing two knives set at and angle that can float to match nearly any thread pitch, and cut at an angle of 60 degrees to match the thread angle. The knives are adjusted by a threaded handle at one end. Coming from the opposite end is an angled roller to engage the opposite side of the thread and force it into the floating knives; you screw the adjustment so as to be able to locate the device past the buggered up threads, then tighten down the adjustment and thread the tool off and over the damaged threads; they work well in most situations, and do not cut so much as they straighten up the threads: this tool has a range of up to about 1 inch. I also have a collection of hand thread chasers; I have heard some call them thread combs; they come in all different pitches, and are used in the lathe with a more or less wood lathe style of rest, and are simply pushed against the rotating threads and the knock off the high spots; it is possible to cut threads from scratch with them, especially in soft metals, but can work in steel also. The art with them is to get them started at the proper pitch, once you get a thread started at the very end of the part, it is fairly easy to continue it to whatever length is needed, with repeated light cutting passes. In the old days these were particularly used in brass work, where most or all the cutting was done with hand tools, by eye.