Indexable rotary cutting tool

A substantially cylindrical tool body (20) having a rotational axis (O), the tool body (20) comprising:

• a spiral groove (28) formed so as to extend from a base end side of the tool body to a leading end side in a peripheral surface (23) of the tool body (20);
• and
• a plurality of insert seats (30) formed so as to be shifted from each other from the base end side toward the leading end side along the spiral groove, wherein:
• the insert seats (30) each comprise a bottom surface (31), a first side surface (32) that intersects with the bottom surface (31) and faces the base end side of the tool body (20), and a second side surface (33) that intersects with the bottom surface and faces the leading end side of the tool body (20), the second side surface (33) being located on the base end side with respect to the first side surface (32),
• in at least one insert seat (30) located closer to the base end side with respect to an insert seat (30) located closest to the leading end side of the tool body (20), a length (L1) of the first side surface (32) is longer than a length (L2) of the second side surface (33), and
• from among the plurality of insert seats (30) in a common spiral groove (28), in at least all the insert seats (30) other than the insert seat (30) located closest to the leading end side and an insert seat (30) located closest to the base end side, the length (L1) of the first side surface (32) is longer than the length (L2) of the second side surface (33).

An indexable rotary cutting tool (10), comprising:

• a substantially cylindrical tool body (20) having a rotational axis (0), the tool body (20) comprising:
• a spiral groove (28) formed so as to extend from a base end side of the tool body to a leading end side in a peripheral surface (23) of the tool body (20);
• and
• a plurality of insert seats (30) formed so as to be shifted from each other from the base end side toward the leading end side along the spiral groove, wherein:
• the insert seats (30) each comprise a bottom surface (31), a first side surface (32) that intersects with the bottom surface (31) and faces the base end side of the tool body (20), and a second side surface (33) that intersects with the bottom surface and faces the leading end side of the tool body (20), the second side surface (33) being located on the base end side with respect to the first side surface (32), and
• in at least one insert seat (30) located closer to the base end side with respect to an insert seat (30) located closest to the leading end side of the tool body (20), a length (L1) of the first side surface (32) is longer than a length (L2) of the second side surface (33), wherein:
• the bottom surface (31) has a substantially triangular shape;
• and
• the first side surface (32) and the second side surface (33) intersect each other at an angle of 60 degrees;
• and
• cutting inserts (40) removably mounted on the insert seats (30) of the tool body (20), wherein the cutting inserts are triangular in shape.

A substantially cylindrical tool body (20) having a rotational axis (O), the tool body (20) comprising:

• a spiral groove (28) formed so as to extend from a base end side of the tool body to a leading end side in a peripheral surface (23) of the tool body (20);
• and
• a plurality of insert seats (30) formed so as to be shifted from each other from the base end side toward the leading end side along the spiral groove, wherein:
• the insert seats (30) each comprise a bottom surface (31), a first side surface (32) that intersects with the bottom surface (31) and faces the base end side of the tool body (20), and a second side surface (33) that intersects with the bottom surface and faces the leading end side of the tool body (20), the second side surface (33) being located on the base end side with respect to the first side surface (32),
• in at least one insert seat (30) located closer to the base end side with respect to an insert seat (30) located closest to the leading end side of the tool body (20), a length (L1) of the first side surface (32) is longer than a length (L2) of the second side surface (33),
• in the at least one insert seat (30) located closer to the base end side, the length (L1) of the first side surface (32) is at least twice as long as length (L2) of the second side surface (33), and
• in the insert seat (30) located closest to the leading end side of the tool body, the length (L2) of the second side surface (33) is at least twice as long as the length (L1) of the first side surface (32).