A central drill insert having rotational symmetry about a central insert axis (I), the central drill insert comprising: a bottom surface having a bottom plane (P), a top surface , and a peripheral surface extending therebetween; at least three lead drill portions protruding outwards from the peripheral surface , each lead drill portion having a drill axis (H) and a plurality of drill cutting edges converging towards the drill axis (H); at least three secondary cutting edges , each adjacent an associated lead drill portion , extending along the intersection of the top surface and the peripheral surface transversely to the respective drill axis (H), each secondary cutting edge being axially spaced apart from the drill cutting edges of the respective lead drill portion along the respective drill axis (H); characterised by : at least three abutment undercuts , each formed on the peripheral surface along the intersection of the bottom surface and the peripheral surface and extending opposite one of the secondary cutting edges ; and at least three abutment flanks formed on the peripheral surface along the intersection of the top surface and the peripheral surface , each extending from one of the lead drill portions towards the secondary cutting edge associated with another lead drill portion , each abutment flank forming a dovetail angle (α) with the bottom plane (P). a bottom surface having a bottom plane (P), a top surface , and a peripheral surface extending therebetween; at least three lead drill portions protruding outwards from the peripheral surface , each lead drill portion having a drill axis (H) and a plurality of drill cutting edges converging towards the drill axis (H); at least three secondary cutting edges , each adjacent an associated lead drill portion , extending along the intersection of the top surface and the peripheral surface transversely to the respective drill axis (H), each secondary cutting edge being axially spaced apart from the drill cutting edges of the respective lead drill portion along the respective drill axis (H); characterised by : at least three abutment undercuts , each formed on the peripheral surface along the intersection of the bottom surface and the peripheral surface and extending opposite one of the secondary cutting edges ; and at least three abutment flanks formed on the peripheral surface along the intersection of the top surface and the peripheral surface , each extending from one of the lead drill portions towards the secondary cutting edge associated with another lead drill portion , each abutment flank forming a dovetail angle (α) with the bottom plane (P). at least three abutment undercuts , each formed on the peripheral surface along the intersection of the bottom surface and the peripheral surface and extending opposite one of the secondary cutting edges ; and at least three abutment flanks formed on the peripheral surface along the intersection of the top surface and the peripheral surface , each extending from one of the lead drill portions towards the secondary cutting edge associated with another lead drill portion , each abutment flank forming a dovetail angle (α) with the bottom plane (P). <EOS>