| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide cutting tap improving a tool service life by reducing edge chipping and chipping due to boundary wear. <P>SOLUTION: In a cutting tap, when a corner 6e at a rake face 6d side in a connection part 6c between a crest top 6a of the final crest of a chamfer part and a leading flank 6b matches with a position 2c where a surface 2b<SB POS="POST">1</SB>at an outer diameter of a full thread part and a surface 2a<SB POS="POST">1</SB>of a taper of the chamfer part cross, a cutting margin A of the final crest of the chamfer part satisfies both expressions of A≥0.63×(TAN(α)×P/F)+TAN(α)×B/2 (I) and A>0.149 mm (II), where the pitch of the cutting tap is P (mm), the number of grooves is F, the width of the top of the crest in the full thread part is B (mm), and the chamfer angle is α (degree). <P>COPYRIGHT: (C)2013,JPO&INPIT |
