Patent ID: 9327353
Filing Date: 2016-05-03
CPC Classification: B23C,Y10T

Claim Text:
1. A roughing and semi-finishing end mill having a longitudinal rotation axis and comprising: a shank portion and a cutting portion extending from the shank portion and being integrally formed with a plurality of cutting teeth alternated with a plurality of flutes; each tooth of the plurality of cutting teeth comprising a rake surface, a relief surface, and a cutting edge formed at an intersection of the rake and relief surfaces; each rake surface comprising a rake recessed sub-surface, a rake cutting sub-surface located further than the rake sub-surface from the rotation axis, and a discontinuity formed at an intersection of the rake recessed and rake cutting sub-surfaces; wherein each tooth of the plurality of cutting teeth comprises an actual internal cutting angle formed at an intersection of the rake cutting sub-surface and the relief surface, the actual internal cutting angle having a greater value than an imaginary internal cutting angle formed at an intersection of imaginary extension lines of the rake recessed sub-surface and the relief surface; wherein each tooth of the plurality of cutting teeth has a rake cutting sub-surface length dimension which is measured from the discontinuity thereof to the cutting edge thereof, the rake cutting sub-surface length dimension having a value less than 5% of the respective tooth's radius dimension which is measured in a straight line from the rotation axis to the cutting edge; wherein the plurality of cutting teeth comprises at least one serrated tooth which is formed with serrations along the relief surface thereof and at least one non-serrated tooth which is free of serrations along the relief surface thereof; and wherein the serrations of the at least one serrated tooth are spaced apart from an end relief thereof by a spacing-distance greater than about half of a peak-distance, the peak-distance being measured between adjacent peaks of the serrations.