Cutting tool

A cutting tool having a tool axis (A) establishing a forward-to-rear direction, the cutting tool comprising a cutting insert and an insert holder,

• the cutting insert having an insert axis (B), and a peripheral side surface comprising a first wall, a second wall, a third wall and at least one operative cutting section,
• the insert holder comprises a forward securing portion and a rear body portion, the forward securing portion comprises a base and securing surface, the securing surface including a first support, a second support and a third support which all extend transversely to the base,
• at least a portion of the first support abuts at least a portion of the first wall along a first abutment region, at least a portion of the second support abuts at least a portion of the second wall along a second abutment region and at least a portion of the third support abuts at least a portion of the third wall along a third abutment region, wherein:
• the first and the second abutment regions diverge downwardly, the second and the third abutment regions diverge rearwardly, and the third wall generally faces upwardly;
• the cutting insert's peripheral side surface is divided into five identical segments, each segment extending between the end surfaces and being located between a pair of adjacent segments;
• and
• each segment has a cutting section located between a leading wall located on leading surface of that segment and a trailing wall located on a trailing surface of that segment.

A method of assembling a cutting tool comprising:

• providing an insert holder comprising a forward securing portion and a rear body portion, the securing portion comprises a base, a hole formed in the base, a lower forward first support, a lower rear second support and an upper third support, a bulge axis of the insert holder intersecting the securing portion adjacent the first and the second supports,
• providing a cutting insert comprising an insert axis, opposing end surfaces, a bore extending along the insert axis between the end surfaces, a first wall, a second wall, a third wall and at least one cutting section, the at least one cutting section comprises a cutting edge located between a rake face and a relief face, the rake face extends rearwardly from the cutting edge and the relief face extends downwardly from the cutting edge and away from the rake face,
• placing the cutting insert in an initial assembly position in the securing portion in which the first wall faces the first support, the second wall faces the second support and the third wall faces the third support,
• placing a fastener through the bore of the cutting insert and into the hole formed in the base of the securing portion,
• urging the cutting insert forwardly and downwardly to an intermediate assembly position in which the first and the second walls respectively bear against the first and the second supports,
• urging the cutting insert further forwardly and downwardly and thereby rotating the cutting insert about the bulge axis until a final assembly position is reached in which the third wall bears against the third support in addition to the first and the second walls respectively bearing against the first and the second supports.

A cutting tool having a tool axis (A) establishing a forward-to-rear direction, the cutting tool comprising a cutting insert having five-fold rotational symmetry seated in an insert holder;

• the cutting insert having an insert axis (B), and comprising:
• two identical opposing end surfaces;
• a through bore extending axially along the insert axis (B) and connecting the two identical opposing end surfaces;
• and
• a peripheral side surface located between the end surfaces and being divided into five identical segments, wherein:
• each segment extends between the end surfaces and is located between a pair of adjacent segments,
• each segment has a cutting section located between a leading wall located on leading surface and a trailing wall located on a trailing surface,
• the trailing surface of one segment and the adjacent leading surface of an adjacent segment meet at a corner which forms a radially innermost portion of the peripheral side surface;
• and
• the trailing surface of a first segment and the adjacent leading surface of a second segment adjacent to the first segment, diverge outwardly from the corner in a direction away from the insert axis (B);
• the insert holder comprising:
• a forward securing portion and a rear body portion,
• the forward securing portion comprises a base and securing surface,
• the securing surface including a first support, a second support and a third support which all extend transversely to the base;
• wherein:
• at least a portion of the first support abuts at least a portion of a trailing wall of a first segment of the cutting insert;
• at least a portion of the second support abuts at least a portion of a leading wall of a second segment of the cutting insert, the second segment being adjacent to the first segment;
• at least a portion of the third support abuts at least a portion of trailing wall of a third segment of the cutting insert, the third segment being adjacent to the second segment;
• and
• the trailing wall of the third segment of the cutting insert generally faces upwardly.