THREAD TAP Russian patent published in 2010 - IPC B23G5/06 

FIELD: technological processes.

SUBSTANCE: thread tap is intended for thread cutting with large pitch and comprises tailpiece, calibrating and cutting parts, having clearance grooves arranged with inclination. Besides calibrating part is arranged without relieving and reverse taper. In order to reduce number of thread taps in set from three to one, remove chips from cut hole, to improve accuracy of cut threads, reduced roughness of cut thread surface, and also to reduce labour intensiveness of thread taps with large pitch, it is arranged as single, length of cutting part is selected as equal to three pitches of thread. Besides number of thread tap wings is selected as equal to four, each thread tap wing has equal front angle along front surface and angle on reverse back edge of wind. Besides front surface is arranged in the form of radius surface, and angle of clearance groove inclination is selected as equal to 38°. Length of calibrating part may be selected as equal to six thread pitches.

EFFECT: reduced number of thread taps in set.

2 cl, 3 dwg