| 摘要 |
A cutting tip, presenting a generally conical body (10), symmetric about a center axis (A) and presenting a profile in a longitudinal section, the said profile comprising a generally convex portion (Pcx), and a generally concave portion (Pcv), The profile of at least one of the generally concave portion (Pcv) and the generally convex portion (Pcx) comprises a first linear portion (LP1, LP5), defined by a portion of a first line, which first line extends from a first point (P1, P12) at an angle of about 45 degrees relative to the center axis (A), to a second point (P2, P11) axially spaced from the first point (P1, P12), and a second linear portion (LP2), defined by a portion of a second line, which second line extends from a third point (P3, P10), forming an approximate middle point of the first line, to a fourth point (P4, P9) at the second radial position and at an axial distance from the second point (P2, P11) corresponding to about half a length of the first line. |
