The ornamental design for a chamferstrip, as shown and described.
FIG. 1 is a front, right perspective view of a chamfer strip showing my new design;
FIG. 2 is a front view thereof;
FIG. 3 is a back view thereof,
FIG. 4 is a right side view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a bottom view thereof; and,
FIG. 7 is a top view thereof.
The chamfer strip can be adapted to a top of a concrete mold. The holes allow nails and screws to fix the chamfer strip to a concrete mold therethrough.