Patent ID: 6685573
Filing Date: 2004-02-03
Classification: B23G,Y10T

Abstract:
A thread forming tap for forming an internal thread by plastic deformation, comprising:an external thread in a screw shape with alternately linked margins and reliefs; and an oil flute established on the external thread; wherein the external thread has a lead angle &agr; and the margins of the external thread have a helix angle &bgr; inclined in a direction opposite to a direction of the helix of the external thread relative to an axis of the tap, and the helix angle &bgr; of the margins is larger than 0Â° and smaller than 10Â° or 4&agr;; and wherein the oil flute is inclined relative to the axis of the tap where an angle and direction of the oil flute are identical to that of the margins on the external thread.