The ornamental design for a cuttinginsert, as shown and described.
FIG. 1 is a perspective view of a cutting insert showing my new design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a left side view thereof;
FIG. 5 is a right side view thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
The broken lines depict portions of the cutting insert that form no part of the claimed design. The dash-dot-dash broken lines define the boundary of the design and form no part of the claimed design. The surface shading in the drawings depict the character or contour of the surfaces represented.