Rotary cutting head having cutting edges extending past key actuating portion

A replaceable milling head (10) rotatable in a cutting direction (RD) about a longitudinal central axis (S) defining a forward direction (F) and an opposite rearward direction (R), the milling head (10) comprising:

• a cutting portion (20), comprising:
• an abutment surface (22), facing in the rearward direction (R) and extending annularly about the central axis (S);
• a peripheral surface (24) extending forward (F) from the abutment surface (22);
• a plurality of chip removal flutes (26) extending along the peripheral surface (24);
• a plurality of cutting edges (28), each extending along a respective chip removal flute (26);
• and
• a first and second key actuating portions (32a, 32c) formed on radially opposite sides of the peripheral surface (24), each of the first and second key actuating portions (32a, 32c) comprising:
• a rearward-facing top shoulder (34a, 34c);
• a forward-facing bottom shoulder (36a, 36c) located rearward of the top shoulder (34a, 34c);
• and
• a bracing surface (38a, 38c) extending between the top shoulder (34a, 34c) to the bottom shoulder (36a, 36c);
• and
• a threaded coupling portion (40), extending rearward (R) of the abutment surface (22);
• wherein
• at least one cutting edge (28) has an active rear cutting edge portion (30) located axially rearward of at least one of the top shoulders (34a, 34c).