The ornamental design for a helicalendmillcutter, as shown and described.
FIG. 1 is a side elevational view of a helical end mill cutter according to
the pressent invention; and,
FIG. 2 is an end, perspective view thereof.
The lower portion of the helical end mill cutter of the present invention
is essentially symmetrical and therefore the other side is not
illustrated. The upper portion thereof is conical and substantially planar
and therefore is not illustrated.