Tread
Tread (also known as crown) means all materials in the tread area of a tire including the rubber that makes up the tread, the sub-base rubber, when present, between the tread base and the top of the belts, the belt material, either steel and/or fabric, and the rubber coating of the same including any rubber inserts, the body ply and its coating rubber under the tread area of the tire, and the inner-liner rubber under the tread.