Indexable cutting insert having two cutting portions located in diagonally opposite quadrants and two lower abutment elements, and cutting tool therefor

A cutting tool (46) comprising:

• an insert holder (48) and an indexable cutting insert (20, 120) removably retained therein,
• the insert holder (48) having a holder head (50, 150) and a holder shank (52) longitudinally extending in a rearward direction (DR) therefrom along a holder axis (AH),
• the holder head (50, 150) having a seat surface (54, 154) and spaced apart first and second male and/or female support elements (56, 58) associated with the seat surface (54, 154),
• the cutting insert (20, 120) having a central mounting portion (22) and first and second cutting portions (24a, 24b),
• the central mounting portion (22) having opposing upper and lower surfaces (26, 126;
• 28), an interconnecting peripheral side surface (30), and an insert axis (AI) passing through the upper and lower surfaces (26, 126;
• 28) defining an upward-to-downward direction (DU, DD),
• the upper surface (26, 126) facing in the upward direction (DU) and having a force application aperture or recess (32) associated therewith,
• the lower surface (28) facing in the downward direction (DD) and having spaced apart first and second male and/or female abutment elements (36a, 36b) associated therewith,
• the first abutment element (36a) having diverging left and right first abutment surfaces (38a, 38b) transverse to the lower surface (28),
• the second abutment element (36b) having diverging left and right second abutment surfaces (40a, 40b) transverse to the lower surface (28),
• the first and second cutting portions (24a, 24b) extending away from the central mounting portion (22) and having distal first and second major cutting edges (42a, 42b;
• 142a, 142b), respectively, and the first and second cutting portions (24a, 24b) being entirely located in diagonally opposite imaginary quadrants (Q1, Q3) of four imaginary quadrants (Q1, Q2, Q3, Q4) defined by mutually perpendicular first and second quadrant planes (PQ1, PQ2) containing the insert axis (AI),
• each cutting portion (24a, 24b) having a rake surface (44a, 44b) adjacent to its respective major cutting edge (42a, 42b;
• 142a, 142b) facing in the upward direction (DU),
• wherein in each index position of the cutting insert (20, 120):
• only one of the two cutting portions (24a, 24b) is operative,
• the lower surface (28) is in contact with the seat surface (54, 154),
• the first and second abutment elements (36a, 36b) occupy or are occupied by the first and second support elements (56, 58), and
• a clamping member (66) engages the clamping aperture or recess (32) and applies a clamping force (FC) thereto.