The ornamental design for a tire tread, as shown and described.
FIG. 1 is a perspective view of the tire tread of our design;
FIG. 2 is a rear view of the tire tread of our design;
FIG. 3 is a side elevational view of the tire tread of our design;
FIG. 4 is a side elevational view of the tire tread of our design, taken from the opposite side of that shown in FIG. 3; and,
FIG. 5 is an enlarged, partial view of FIG. 1.
In the drawings, the broken lines depict environmental subject matter that forms no part of the claimed design. The dash-dot lines represent the peripheral boundary between the claimed tire tread and the unclaimed sidewall. The tread pattern is understood to repeat uniformly throughout the circumference of the tire, as shown schematically in solid lines.