The ornamental design for a lockinghead of wire, as shown and described.
FIG. 1 is a perspective view of a locking head of wire 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.
The broken lines immediately adjacent to the claimed areas represent the boundaries of the design. The broken lines environment is for illustrative purpose only. None of the broken lines form part of the claimed design.