TAP FOR CUTTING OF THREAD IN BLIND HOLES Russian patent published in 1999 - IPC

FIELD: mechanical engineering. SUBSTANCE: tap may be used for cutting of blind threads under conditions of automatically-controlled production especially in treatment of viscous constructional materials. Two perpendicular slit-like recesses, depth of which equals 0.3-0.6 the length of tap cutting edge are made from side of tap end face along cutting part axis including roll- threading lip. Width of recesses makes up 0.1-0.5 mm, smaller value corresponding to small-diameter taps. Given construction allows of tap dynamic rigidness in its cutting part in process of thread cutting. EFFECT: enhanced reliability of operation. 4 dwg