Endmill Design Basics – Mastercut Tool Corp
WEBClearance: Primary (first angle 5 – 9 degree) – Relief adjacent to the cutting edge. Clearance: Secondary (2nd angle 14 – 17 degrees) – Relief adjacent to the cutting edge. Clearance: Tertiary ( 3rd) – Additional relief clearance provided adjacent to the secondary angle. Concave – Small hollow required on the end face of an Endmill.