Insert holder having weight-reducing voids and cutting tool

An insert holder (22), elongated along a holder longitudinal axis (B) thereof, the holder longitudinal axis (B) defining opposite forward and rearward directions (DF, DR), the insert holder (22) having monolithic construction and comprising:

• a holder forward end surface (28), a holder rearward end surface (30) and a holder peripheral surface (36) extending therebetween, the holder peripheral surface (36) extending about the holder longitudinal axis (B);
• a cutting portion (38) comprising an insert pocket (42), for releasably retaining a cutting insert (24), the cutting portion (38) located at a forward end (32) of the insert holder (22);
• a shank portion (46) extending rearwardly from a shank axial abutment surface (54) at a rearward end of the cutting portion (38), the shank axial abutment surface (54) perpendicular to the holder longitudinal axis (B), the holder peripheral surface (36) at the shank portion (46) comprising a shank radial centering surface (48), the entire shank portion (46) configured to be located in a tool receiving recess of a tool holder, the shank portion (46) releasably clamped therein with the shank radial centering surface (48) abutting a recess abutment surface of the tool receiving recess;
• and
• a weight-reducing cavity (56) comprising:
• a cavity chamber (58) enclosed within the insert holder (22), the cavity chamber (58) comprising a chamber interior wall surface (60);
• and
• a plurality of cavity through recesses (66) opening out to:
• (i) the chamber interior wall surface (60) thereby forming a plurality of inner recess openings (70), and to (ii) the shank radial centering surface (48) thereby forming a plurality of outer recess openings (72);
• wherein:
• an entirety of the weight-reducing cavity (56) is located in the shank portion (46), rearward of the cutting portion (38),
• the plurality of cavity through recesses (66) extending helically about the holder longitudinal axis (B) along a respective through recess longitudinal axis defined by each cavity through recess (66),
• the cutting portion (38) comprises a plurality of flutes (44) recessed in the holder peripheral surface (36), and
• the plurality of flutes (44) extend helically about the holder longitudinal axis (B) in the same helical direction as the plurality of helically-extending cavity through recesses (66).