1、Designation:B957/B957M19Standard Specification forExtra-High-Strength and Ultra-High-Strength Zinc-Coated(Galvanized)Steel Core Wire for Overhead ElectricalConductors1This standard is issued under the fixed designation B957/B957M;the number immediately following the designation indicates the yearof
2、original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This specification covers round,extra-high-strength andultra-high
3、-strength,Class A zinc-coated(galvanized),steelcore wire used for use in Overhead Electrical Conductors.1.2 This specification covers wire of diameter from 0.0500to 0.1900 in.inclusive or 1.27 to 4.82 mm inclusive.1.3 The values stated in either SI units or inch-pound unitsare to be regarded separat
4、ely as standard.The values stated ineach system may not be exact equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems may result in non-conformancewith the standard.1.4 This standard does not purport to address all of thesafety concerns,if an
5、y,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accor-dance with internationally
6、 recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2A90/A90M Test Metho
7、d for Weight Mass of Coating onIron and Steel Articles with Zinc or Zinc-Alloy CoatingsA370 Test Methods and Definitions for Mechanical Testingof Steel ProductsA751 Test Methods,Practices,and Terminology for Chemi-cal Analysis of Steel ProductsB6 Specification for ZincB193 Test Method for Resistivit
8、y of Electrical ConductorMaterialsE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with Specifications3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 Lot,nUnless otherwise specified in the contract ororder,a lot shall consist of all coils of wire o
9、f the samediameter and unit lengths submitted for inspection at the sametime.3.1.2 Product Code,nDefines product coating type,coat-ing class and strength grade.3.1.2.1 Extra High Strength Grade Zinc,Class A Coateduse Code GA4.3.1.2.2 Ultra High Strength Grade Zinc,Class A Coateduse Code GA5.4.Orderi
10、ng Information4.1 Orders for material under this specification shall includethe following information:4.1.1 Quantity of each size,4.1.2 Wire diameter in inches or millimeter(Section 13),4.1.3 Certification,if required(Section 18),4.1.4 Test report,if required(Section 18),and4.1.5 Package size(Sectio
11、n 19).4.1.6 Strength Grade.5.Materials and Manufacture5.1 The base metal shall be steel produced by the open-hearth,electric-furnace,or basic-oxygen process.5.2 The wire shall be cold drawn and coated with zinc toproduce the desired properties.5.3 The slab zinc used for coating shall be high grade o
12、rbetter,conforming to Specification B6.1This specification is under the jurisdiction of ASTM Committee B01 onElectrical Conductors and is the direct responsibility of Subcommittee B01.05 onConductors of Ferrous Metals.Current edition approved March 1,2019.Published March 2019.Originallyapproved in 2
13、008.Last previous edition approved in 2016 as B957 16.DOI:10.1520/B0957_B0957M-19.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page ont
14、he ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopme
15、nt of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 6.Chemical Composition6.1 The steel shall conform to the requirements prescribedin Table 1.6.2 Chemical analysis shall be conducted in accordancewith Test Metho
16、ds,Practices,and Terminology A751.7.Tensile Test7.1 The zinc-coated steel core wire shall conform to theordered tensile and elongation requirements prescribed inTable 2,Table 3,Table 4,or Table 5 and a minimum breakingstrength(lbs N)calculated from the minimum requiredtensile and nominal wire diameter.The wire tensile strengthused to determine compliance to Table 2,Table 3,Table 4,orTable 5 shall be calculated using the actual wire breakingstrength and the nominal finished diameter of the wire.7
