The ornamental design for a tire tread, as shown and described.
FIG. 1 is a partial perspective view of a tire tread showing my new invention;
FIG. 2 is a left side elevation view thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a right side elevation view thereof; and,
FIG. 5 is a front view thereof.
The tire tread is continuously formed around the entire circumference of the tire as shown schematically in solid lines in the drawings.
The dashed lines indicate a vehicle tire upon which the tire tread is formed, but the dashed subject matter does not form a part of the claimed invention.