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In climb milling the end mill rotates in the direction of the feed. The
tooth meets the work at the top of the cut at the thickest portion
of the chip. This provides instant engagement of the end mill with
the workpiece producing a chip of definite thickness at the start
of the cut without the rubbing action resulting from conventional
milling. It further permits the gradual disengagement of the teeth
and work so that feed marks are largely eliminated.
Climb milling will often provide better product finish, permit greater
feed per tooth and prolong the cutter life per sharpening. It is
particularly desirable to climb mill such materials as heat treated
alloy steels and non-free machining grades of stainless steel for
better tool life and to reduce work hardening. It is not recom-
mended on material having a hard scale, such as cast or scaly
forged surfaces, because abrasion would quickly ruin the cut-
ting edges. Also some very soft steels do not lend themselves to
climb milling because of their tendency to drag and tear.
Climb milling cannot be applied to every milling operation and
should not be attempted if the material and the machine setup are
not adapted to this type of milling.
