The ornamental design for a tire tread, as shown and described.
FIG. 1 is a first perspective view of a full tire including the tire tread and particularly illustrating a first side of the present application;
FIG. 2 a second perspective view of the full tire including the tire tread and particularly illustrating a second side thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a side view of the first side thereof; and,
FIG. 5 is a side view of the second side thereof.
The broken lines and the region therebetween defining the inner bead and the sidewall depict subject matter that forms no part of the claimed tire tread design, and are included for the purpose of illustrating the full tire. The tread pattern is understood to repeat throughout the circumference of the tire.