The ornamental design for a tire tread, as shown and described.
FIG. 1 is a perspective view of a tire tread showing my new design, it being understood that the tread pattern repeats circumferentially throughout the outer circumference and shoulder of a tire, the opposite side perspective view being identical thereto;
FIG. 2 is a full front elevation view of the tire tread of FIG. 1; and,
FIG. 3 is a side view of the tire tread of FIG. 1.
In the drawings, the dark stippled surface shading represents the recessed groove portions of the tire tread having a depth as best illustrated along the top and bottom edges of FIG. 2. The broken line disclosure of the tire sidewall and inner bead is for illustrative purposes only and forms no part of the claimed design.