The ornamental design for a tire tread, as shown and described.
FIG. 1 is a perspective view of a tire tread showing our new design, it being understood that a tread pattern is repeated over the outer circumference of the tread width on one lateral side of the mid-circumferential plane of the tire and the adjacent shoulder of the tire; and,
FIG. 2 is a enlarged fragmentary front elevation view of the tread pattern of FIG. 1.
The broken line disclosure of a tire sidewall and inner bead and the broken lines on the other lateral side of the mid-circumferential plane over the tread width are for illustrative purposes only and form no part of the claimed design.