This specification covers two sizes of extra-high-strength grade of concentric-lay steel wire strand, composed of seven, zinc-coated steel wires, specifically intended for use as the supporting messenger in Figure 8-type communication and electrical cables. Steel wires shall be manufactured by the open-hearth, basic-oxygen, or electric-furnace process. Materials shall adhere to specified mechanical and physical requirements such as breaking strength, elongation, ductility, nominal diameter, and coating weight and adherence. Zinc coatings shall be continuous and of reasonably uniform thickness, and wires shall be free from imperfections not consistent with good commercial practice.

1.1 This specification covers two sizes of extra-high-strength grade of concentric-lay steel wire strand, composed of seven, zinc-coated steel wires, specifically intended for use as the supporting messenger in Figure 8-type communication and electrical cables.

1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.