Abstract: The invention relates to a shell end mill with a holder (12), a two-piece cylindrical cutting section (10) releasably secured to the holder (12), at least two helical chip grooves (18) at a circumferential distance apart in the cutting section (10), a set of substantially radial base support surfaces (22) arranged one behind the other along a chip groove side and a insert seat (20) with radially limiting side support surfaces on the groove base side to take indexable inserts (24) in an arrangement of axially overlapping pairs. The inner tips (24) arranged behind the outermost frontal indexable inserts (24') are axially clamped to the insert seats without abutment. In particular, the frontally inoperative cut (42) of the inner indexable inserts (24) engages without abutment in a back-cut (46) in the adjacent insert seat.