The ornamental design for a tire tread, as shown and described.
FIG. 1 is a perspective view of a tire tread showing my new design, it being understood that the pattern is repeated throughout the circumference of the tread, the opposite side being substantially the same as that shown;
FIG. 2 is a front elevational view thereof;
FIG. 3 is an enlarged fragmentary front elevational view thereof illustrating the pitching of the tread blocks; and
FIGS. 4 and 5 are enlarged fragmentary side elevational views thereof.
The broken lines in the drawings are for illustrative purposes only and form no part of the claimed design.