The ornamental design for a tire tread, as shown and described.
FIG. 1 is a perspective view of a full tire including the tire tread of the present application;
FIG. 2 is a side view thereof;
FIG. 3 is a front view thereof; and,
FIG. 4 is an enlarged partial front view thereof.
The side views of 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.