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;
FIG. 2 is a front view thereof;
FIG. 3 is a top view thereof;
FIG. 4 is a right side view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a fragmentary enlarged front view thereof; and,
FIG. 7 is an end view taken along line 7-7 in FIG.6 thereof.
The dash-dash broken lines showing portions of the tire tread are for the purpose of illustrating environmental structure and form no part of the claimed design. The dash-dot-dash broken lines represent the boundary of the claimed design and form no part of the claimed design. The light stippled surface shading represents the surface of the tire tread, and the dark stippled surface shading represents the recessed portion of the tread grooves, having the depth as shown in FIG. 7.