摘要 |
An indexible cutting bit includes an upper side of polygonal contour defining at respective corners thereof a secondary cutting edge which extends between first and second main cutting edges. The secondary cutting edge includes, in order of closeness to the first main cutting edge: a convexly curved transition first portion extending from an end of the first main cutting edge, a concavely curved second portion of a second radius, a convexly curved third portion of a third radius, a concavely curved fourth portion of a fourth radius, a convexly curved fifth portion of a fifth radius, a concavely curved sixth portion of a sixth radius, and a convexly curved transition seventh portion extending to the second main cutting edge.
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