Abstract: Disclosed is a fastener having a base portion and at least two anchor legs projecting from the base portion in the same general direction. At least one barb-like projection is disposed on at least one pair of the pairs of surfaces of the group comprising the remote surfaces on the outer sides of the legs and the proximate surfaces on the inner sides of the legs. Saddle surfaces begin at the one pair of surfaces and slant toward the other, opposite surfaces of the legs as they approach the free ends of the legs. Shoulder surfaces on at least the other of the pairs of surfaces of the group are generally opposite the saddle surfaces and are slanted toward the free ends of the legs, so that they form wedge-like cutting edges with the saddle surfaces at the end portions of the anchor legs.