The ornamental design for a tire tread, as shown and described.
FIG. 1 is a partial perspective view of the tire tread showing our new design, it being understood that the pattern repeats uniformly throughout the circumference of the tread;
FIG. 2 is a side view thereof;
FIG. 3 is a front partial view thereof; and,
FIG. 4 is an enlarged front view of the tire tread.
The inner and outer sides of the tire are the same, i.e., the tire tread is symmetrical. The broken line showings of the sidewall, inner bead, shoulder tread, and the peripheral boundary between the tire tread and the sidewall is included for the purpose of illustrating environment and forms no part of the claim.