The ornamental design for a tire tread, as shown and described.
FIG. 1 is a front elevational view of a tire tread showing the new design on the face of a tire; and,
FIG. 2 is a perspective view thereof.
In the drawings, the evenly-spaced broken lines depict portions of a tire that form no part of the claim; the dash/dot/dash broken lines depict boundaries of the claim and form no part thereof. The design continues uniformly throughout the circumference of the tire, as shown schematically in solid lines in the drawings. The claimed design is only visible on the exterior face of the tire and consists of a repeating pattern which appears identical no matter which section of the tire face is viewed.