摘要 |
A cutting insert for a gauge row of a percussion drill bit includes a generally cylindrical mounting portion (24) extending along a central axis and a cutting head (28) extending from the mounting portion. The head has an exposed surface (30) forming a non-symmetrical dome shape such that the working portion (32) of the head is enlarged with respect to a standard dome shape and a trailing portion (34) is reduced with respect to a standard dome shape. The cutting head has an inner (36) and an outer edge (38). The exposed surface is non-symmetrical along a central plane (44) which bisects the working (32) and trailing portion (34). The exposed surface (30) is symmetrical in second plane perpendicular (7, 8, 9) to the central plane such that the exposed surface (30) forms an arc of constant radius from the inner edge (36) to the outer edge (38) in the second planes (7, 8, 9).
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