ASTM B979 - 12(2026)

1.1 This specification covers non-specular surface finishes on overhead aluminum electrical conductors. Overhead aluminum electrical conductors, when installed, typically have a shiny surface appearance. This “reflective” or “specular” surface can make a transmission line more noticeable in appearance against the background landscape. A factory treatment process of the outer surface of the aluminum wires can render the surface finish into a dull, non-reflective, matte grey finish. This non-reflective or “de-glared” surface finish allows the conductor to become less visible when observed from a distance and enables the transmission line to blend in with the skyline or landscape background.

1.2 This specification is intended, by means of diffuse reflectance measurement, to establish a uniformity of conductor finish which is acceptable to the user. Such a specification will furnish a basis for consistent manufacturing process control.

1.3 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.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.5 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.