PURPOSE: To provide longer life of a tool, by bending a serrated side face to form a projectingly curved face, for increasing the included angle and the nose strength of spiral shaping edges.
CONSTITUTION: The upper and the lower faces 16, 17 of a chip 14 for thread cutting are formed to be flat faces which are parallel with each other, the side face 21 is formed to be serrated, and rows of spiral shaping edges 22, 23 are formed on the cross-ridge lines between the side face 21 and the upper face 16, and between the side face 21 and the lower face 17. This side face 21 is bent to form a circular arc, which is symmetrically shaped with a section passing through the center of the thickness of the chip 14, between the upper and the lower faces 16, 17, as a center face. With this structure, the included angle of the spiral shaping edges 22, 23 is increased and the strength of them is also increased, and consequently, life of the tool is lengthened.
| JP4699665 | Cutting insert for grooving |
| JP6743440 | Bit and bite manufacturing method |
| WO/1998/030349 | CUTTING INSERT AND HOLDER FOR METAL CUTTING MACHINING |
ARAI TATSUO
SAITOU TAKANOBU
MIYABAYASHI MITSUYUKI
MITSUI MASAO
YAMAWA MFG