Tool holder

A tool holder, comprising:

• a body having a body inner peripheral surface, a body outer peripheral surface, a shank portion on a first end side, a tool gripping portion on a second end side that is opposite of the first end side in an axial direction of the body, and a first elastic portion interposed between the shank portion and the tool gripping portion in the axial direction of the body and configured to be elastically deformable along the axial direction and around a circumferential direction of the body;
• wherein:
• a plurality of first voids and a plurality of second voids are defined within the first elastic portion between the body inner peripheral surface and the body outer peripheral surface,
• at least two of the first voids extend along the circumferential direction so as to at least partially overlap with each other in the circumferential direction of the body,
• at least two of the second voids extend along the axial direction so as to at least partially overlap with each other in the axial direction of the body,
• a plurality of first void groups includes a first sub-set of the first voids and a first sub-set of the second voids,
• a plurality of second void groups includes a second sub-set of the first voids and a second sub-set of the second voids,
• in each of the first void groups, at least one of the first voids is continuous with at least one of the second voids,
• in each of the second void groups, at least one of the first voids is continuous with at least one of the second voids, and
• the first void groups and the second void groups are alternately arranged around the circumferential direction such that the first void group and the second void group that are adjacent to each other in the circumferential direction partially overlap with each other in the circumferential direction and in the axial direction of the body.

A tool holder comprising a steel tubular body having:

• a shank on a first axial end portion,
• a tool gripping portion on a second axial end portion, and
• an elastic segment interposed between the shank and the tool gripping portion in the axial direction of the body, the elastic segment being more elastically deformable along the axial direction and around a circumferential direction of the steel tubular body than the shank and the tool gripping portion;
• wherein:
• a plurality of voids extend through the elastic segment from an outer peripheral side of the steel tubular body to an inner peripheral side of the steel tubular body,
• each of the plurality of voids includes:
• (i) at least two axially-extending void segments that extend at least substantially along the axial direction of the steel tubular body in parallel with each other and (ii) at least two circumferentially-extending void segments that extend at least substantially around the circumferential direction of the steel tubular body in parallel with each other,
• in each of the plurality of voids, the at least two axially-extending void segments are continuous with the at least two circumferentially-extending void segments,
• at least one of the axially-extending void segments of each of the plurality of voids extends between at least two of the axially-extending void segments of another of the plurality of voids, and
• at least one of the circumferentially-extending void segments of each of the plurality of voids extends between at least two of the circumferentially-extending void segments of another of the plurality of voids.