1.1 This specification covers uncoated, high-strength, hard-drawn steel wire for use in the construction of prestressed concrete tanks and similar structures. In application, the wire is continuously wrapped on the structure maintaining tension by a device using a wire drawing die, or mechanical tensioning system without re-drawing.

1.2 This specification is applicable only to the condition of the wire as delivered to the purchaser. It is not applicable to the properties or condition of the wire after application.

1.3 The text of this standard references notes and footnotes which provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the standard.

1.4 This specification is applicable for orders in either inch-pounds units (as Specification A821) or in SI units (as Specification A821M).

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