ASTM B520-12(2023) PDF

ABSTRACT This specification covers tin-coated, copper-clad steel wires for electronic applications. The four classes of steel wires considered here are: hard-drawn wires with 30% nominal conductivity (Class T30HS); annealed wires with 30% nominal conductivity (Class T30A); hard-drawn wires with 40% nominal conductivity (Class T40HS); and annealed wires with 40% nominal conductivity (Class T40A). Specimens shall go through tests and shall adhere to specified requirements for dimensions, electrical resistivity, tensile strength, and coating continuity and adherence. SCOPE 1.1 This specification covers tin-coated copper-clad steel wire for electronic application. 1.2 Four classes of tin-coated copper-clad steel wire are covered as follows: 1.2.1 Class T30HS—Nominal 30 % conductivity, hard-drawn, 1.2.2 Class T30A—Nominal 30 % conductivity, annealed, 1.2.3 Class T40HS—Nominal 40 % conductivity, hard-drawn, and 1.2.4 Class T40A—Nominal 40 % conductivity, annealed. 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. 1.3.1 Exception—The SI values for resistivity and volume are to be regarded as standard. 1.4 The following safety hazards caveat pertains only to the test method portion, Section 6, of this specification: 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. (Warning—Consideration should be given to toxicity and flammability when selecting solvent cleaners.) 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.