ASTM E1136-93(2003),Standard Specification for A Radial Standard Reference Test Tire.
ASTM E1136-93(2003) covers the general requirements for a radial-ply standard reference test tire.
Materials and Manufacture
The individual standard reference test tires shall conform to the manufacturer’s design standards. Dimensions,weights, and permissible variations are given in Section 7 and Table 1 and Table 2.
Tread compounding, fabric processing, and all the steps in tire manufacturing shall be controlled to ensure minimum variability between tires.
The standard reference test tire shall be as originally molded without any tread grinding or repairs.
ASTM E1136-93(2003) pdf can be downloaded here.