ROTARY CUTTING TOOL AND REVERSIBLE CUTTING INSERT HAVING VARIABLE-WIDTH MINOR RELIEF SURFACES THEREFOR

摘要

In the rotary cutting tool 52 used in the milling process, the reversible cutting insert 20 is detachably fixed to the cutting body 54. The cutting insert 20 has two opposite end faces 22 interconnected by a continuous outer face 24 and the outer face 24 has three sides 28 alternating with the three corner faces 28, (26). Side 26 and corner 28 intersect both end edges 22 at side edges 32 and corner edges 34 and each side edge 32 has a major cutting edge 36, Each corner edge 34 has a corner cutting edge 38 and a minor cutting edge 40. Each sub-cutting edge 40 has a projected minor cutting length L _M and each associated sub-relief surface 48 has a minor relief width B between two lateral boundary points contained in the horizontal plane PH. (W), the minor relief width W changes in accordance with the offset distance Do between the horizontal plane PH and the center plane M. Each projected minor cutting length L _M is greater than the maximum partial relief width W _MAX of the associated relief surface 48.