The ornamental design for a fastenerhead, as shown and described.
FIG. 1 is an top perspective view of the fastener head embodying the new design;
FIG. 2 is an enlarged perspective view thereof taken from indication circle 2 of FIG. 1;
FIG. 3 is a second perspective view of FIG. 2;
FIG. 4 is a side view of FIG. 1;
FIG. 5 is an enlarged side view thereof taken from indication box 5 of FIG. 4;
FIG. 6 is a top view of FIG. 2; and,
FIG. 7 is a cross section view of FIG. 2 taken from 7-7 of FIG. 6.
The broken lines rendered in the drawings illustrates the environment of the claimed design and forms no part thereof. The broken lines immediately adjacent the solid line portions of the design define the bounds of the claim and form no part thereof.