Osg Corporation

Tunalogy Corporation

Katsutoshi Watanabe

Tasuku Itoh

Yasuo Hamatake

Jiro Osawa

Tamotsu Nagai

Masuo Saitoh

Satoru Yoshida

In a semi-finishing cutter, rectangular tips and square tips are disposed in a staggered pattern in an axial direction in second to fourth step portions, so a single cutting edge is formed by a pair of one of the rectangular tips and one of the square tips. It is therefore possible to effectively reduce a frequency of contact with a blade root. A cutting speed of the semi-finishing cutter may be increased and a cutting feed may be made faster, so work in a semi-finishing process may be performed efficiently. The rectangular tips and the square tips have simple shapes, so known commercially available throwaway tips may be used. Accordingly, it is possible to provide the semi-finishing cutter in an easy-to-use form without increasing the cost.

Throwaway rotary cutting tool

In a rough cutting cutter, square tips and rectangular tips are disposed in a staggered pattern in an axial direction in second to fourth step portions, so a cutting edge is formed by a pair of one of the square tips and one of the rectangular tips. It is therefore possible to effectively reduce a frequency of contact with a blade root. Furthermore, in the second to a fifth step portions, ARs (rake angles in the axial direction) and RRs (rake angles in a radial direction) of the square tips and the rectangular tips gradually increase in order from a tip end to a back end of a tool body. It is therefore possible to suppress chatter vibration during machining and is possible to reduce roughness of a cut surface of a work material.

A cutting insert is provided with at least a circular-arc blade cutting edge as a cutting edge in the form of a substantially quarter circular arc, at an intersection between a rake face and a flank face, and an outer cutting edge extending from one end portion of the circular-arc cutting edge. The rake face is formed so as to be convex in a direction of rotation when the cutting insert is mounted on a tool body. On a section perpendicular to the cutting edge, the rake face is inclined so as to become gentler with distance from the circular-arc cutting edge or outer cutting edge. The circular-arc cutting edge is formed to be convex in the direction of rotation. The outer cutting edge is formed so that its edge ridge line is substantially parallel to the axis of the tool body.

Cutting insert for radius cutter and indexable-insert radius cutter fitted with the same

A cutting tool including a cutter head and a holder. One of the cutter head and the holder has a recess formed in its axial end portion and defined by its circumferential wall. The other of the cutter head and the holder has a protrusion formed in its axial end portion, such that the cutter head and the holder are detachably attached to each other, with the protrusion being introduced in the recess by an axial distance. The above-described one has coaxial holes formed in the circumferential wall. The above-described other has an engaging surface which is recessed from an outer circumferential surface of the protrusion and which is held in engagement with a pin that is received in the coaxial holes. Each of the coaxial holes has an axis which is inclined, with respect to a plane perpendicular to an axis of the above-described one, in a direction causing the above-described axial distance to be increased by a cutting resistance generated in a cutting operation.

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Toyokawa, Japan

Katsutoshi Watanabe