PURPOSE: To enable the manufacture of a reusable cold forming tap by dividing axial protrusion groups into plural sets consisting of plural protrusion groups present at equal intervals around the shaft center and providing the chamfer of each group shifted to each other in the axial direction.

CONSTITUTION: Six protrusion groups 22 are divided into two sets of protrusion groups 22a, 22c, 22e and 22b, 22d, 22f present every other group around the shaft center of a cold forming tap 10, the chamfer part 14 of one protrusion group 22b, 22d, 22f is provided in the position shifted by the portion for two crests toward the base end side. When the life of the chamfer part 14 of the protrusion group 22a, 22c, 22e is expired by abrasion and failure, their chamfer part 14 and a part of a perfect crest part 12 are ground and removed for two crests or more, and the top end part of the cold forming tap 10 is cut for two crests. Therefore, the cold forming tap 10 has the chamfer part 14 of the protruded group 22b, 22d, 22f situated on the top end side. Thus, the formation of a female screw is made possible again by the chamfer part 14 of the protrusion group 22b, 22d, 22f newly situated on the top end side.