The ornamental design for a tire tread, as shown and described.
FIG. 1 is a perspective view of a tire tread showing our new design, it being understood that the tread is repeated throughout the circumference of the tire, the opposite side perspective being identical thereto, it being understood that the broken lines represent environment and form no part of the claimed design;
FIG. 2 is a front elevation view thereof, the rear elevation being identical thereto;
FIG. 3 is a side elevation view thereof, the opposite side elevation being identical thereto;
FIG. 4 is a perspective view of a tire including our new tread design, the opposite side perspective being identical thereto;
FIG. 5 is a front elevation view of said tire; the rear elevation being identical thereto;
FIG. 6 is a side elevation view of said tire, the opposite side elevation being identical thereto; and,
FIG. 7 is a section view of said tire taken along line 7-7 shown in FIG. 5.