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 pattern is repeated over the outer circumference and shoulder of the tire, the opposite side perspective view being identical thereto; and,
FIG. 2 is an enlarged fragmentary front elevation view of the tread pattern of FIG. 1.
In the drawings, the dark stippled surface shading represents the recessed portion of the tread grooves, having a depth as best shown along the right edge of FIG 1. The broken line disclosure of a tire sidewall and inner bead is for illustrative purposes only and forms no part of the claimed design.