TAP

• Main Author: FUJI MASAYUKI
• Format: Patent
• Language: English
• Published: 19.01.2012
• Subjects: MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR; PERFORMING OPERATIONS; THREAD CUTTING; TRANSPORTING; WORKING OF SCREWS, BOLT HEADS, OR NUTS, IN CONJUNCTIONTHEREWITH

PROBLEM TO BE SOLVED: To provide a low-cost tap which can connect a cutting edge part with a shank part again in a short period of time when the connection between the cutting edge part and the shank part fails, and further which can prevent deterioration of screw-processing accuracy of nuts by suppressing deflection of the tap to be smaller.SOLUTION: A bent shank tap 1 or a straight tap 2 includes: the cutting edge part 3 in which a joint portion 5 at the proximal end is formed and threaded with a smaller diameter; the shank part 8 in which a joint portion 11 at the top end is formed and threaded with a smaller diameter; and a joint pipe 6 in which the joint portion 5 and the joint portion 11 are respectively screwed at both ends and the cutting edge part 3 and the shank part 8 are integrally connected. The joint pipe 6 has a recess 14 formed as a breaking groove to be broken when an unusual torque is applied to the cutting edge part 3. The cutting edge part 3 and the shank part 8 have stepped surfaces 7 and 12, respectively, formed as abutting faces in the vicinity of their outer circumferences so that the abutting faces come in contact with the end surfaces 15 of the joint pipe 6 when the joint portion 5 and the joint portion 11 are screwed into the joint pipe 6.