Each set contains five taps: .255-28 (+.005), .260-28 (+.010), .265-28 (+.015), .270-28 (+.020), .275-28 (+.025) over size 1/4-28 taps.
These are thread reforming taps. Use these taps, in sequence, to clean up a 1/4-28 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. Use tapping fluid. Properly used, these should last a lifetime. They can be carelessly damaged, chipped, broken, and dulled. Not warranted against failure. Repairs are best performed by skilled gunsmiths, experienced machinists, or serious hobbyists.
