The ornamental design for a tire tread, as shown and described.
FIG. 1 is a perspective view of the tire tread of my design;
FIG. 2 is a front elevation view of the tire tread of my design;
FIG. 3 is a side elevation view of the tire tread of my design;
FIG. 4 is a side elevation view of the tire tread of my 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 dash-dash broken line disclosure depicts environmental structure and forms no part of the claimed design. The dash-dot-dot-dash 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.