The ornamental design for a tire tread, as shown and described.
FIG. 1 is a front elevational view of a tire tread, it being understood that the tread pattern is repeated throughout the circumference of the tire tread, the opposite side being the same as that shown.
FIG. 2 is a front angled perspective view of the tire tread, it being understood that the tread pattern is repeated throughout the circumference of the tire tread; and,
FIG. 3 is a side elevational view of the right side of the tire tread, the opposite side being identical thereto.
In the drawings, the evenly dashed broken lines defining the sidewall and inner bead depict environment that forms no part of the claimed design. The unevenly dashed broken line represents the peripheral boundary between the claimed tire tread and the sidewall which forms no part of the claim.