1.1 This specification covers uncoated stress-relieved steel bars for use in prestressed concrete railroad ties.

1.2 A supplementary requirement (S1) is provided for use where low-relaxation bars and relaxation testing for that product is required by the purchaser. The supplementary requirement applies only when specified in the purchase order or contract.

1.3 This specification is applicable for orders in either inch-pounds units (as Specification A911) or in SI units (as Specification A911M).

1.4 The values stated in either inch-pound units or SI units are to be regarded separately as standards. Within the text, the SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with the specification.