Rotatable cutting head having tip portion with radially extending cutting edges forming a cutting profile having concave and convex sub-portions

Abstract

A cutting head rotatable about a central axis, includes a tip portion and an intermediate portion. The tip portion has an axially forwardmost tip point contained in the central axis and at least two axially forward-facing front surfaces, each front surface having a radially extending cutting edge. The intermediate portion has at least two head lands circumferentially alternating with at least two chip evacuation passages, each head land having a leading edge extending axially rearwardly from the tip portion. The cutting edges are contained in an imaginary annular ring surface, and a first imaginary radial plane containing the central axis intersects the imaginary annular ring surface to form two imaginary radial cutting profiles. Each imaginary radial cutting profile has consecutively radially outward extending first, second, and third cutting profile portions, and the second cutting profile portion includes first and second concave sub-portions spaced apart by a first convex sub-portion.