A high-speed forming tap (1) for cutting and forming a female screw by
cutting edges (E) of a screw portion (2) fed in synchronous with the
rotation of a machine tool. The high-speed forming tap is characterized
in that chamfers (CF) are provided at a bevel lead (2a) of the screw part
(2). The chamfers (CF) start from the cutting edge (E) and are provided
along ridgelines (R) between a crest face (2e) and flanks, or a following
flank (2c) and a leading flank (2d). This structure enables the shape of
the edges of the tap leading portion to be stably maintained and
high-speed, smooth female screw cutting with high accuracy, and provides
a tap with long life.