Best used in sequence, to clean up a 1/4x28 thread. Install one of our matching oversize nipples. Never use a standard nipple in an oversize hole! Never use these taps to thread a new hole. Stop when threads are fully restored. Don't enlarge nipple seats unnecessarily.
Sturdy hardened steel. Use a tap handle. Properly used, these should last a lifetime. They can be carelessly damaged, chipped, broken, or dulled. Not warranted against failure. Repairs are best performed by skilled gunsmiths, experienced machinists, or serious hobbyists.