This Standard covers roller chains that are specifically designed to withstand occasional high shock loads, or high starting loads, that are encountered in certain construction equipment and other severe-duty applications. WARNING: Chains covered in this Standard shall not be used as the primary lifting member, or in the direct drive line of elevators, escalators, or similar devices for lifting human passengers unless applied in accordance with ASME A17.1. Chains covered in this Standard shall not be used as climbing chains.