ASTM B957-08

Standard Specification for Extra-High-Strength and Ultra-High-Strength Zinc-Coated (Galvanized) Steel Core Wire for Overhead Electrical Conductors

SCOPE
1.1 This specification covers round, extra-high-strength and ultra-high-strength, Class A zinc-coated (galvanized), steel core wire used for use in Overhead Electrical Conductors.
1.2 This specification covers wire of diameter from 0.0500 to 0.1900 in. inclusive or 1.27 to 4.82 mm inclusive.
1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. 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.
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 and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 31-Oct-2008
• ICS: 77.140.65 - Steel wire, wire ropes and link chains
• Technical Committee: B01 - Electrical Conductors
• Drafting Committee: B01.05 - Conductors of Ferrous Metals

Relations

• Replaced By: ASTM B957/B957M-08e1 - Standard Specification for Extra-High-Strength and Ultra-High-Strength Zinc-Coated (Galvanized) Steel Core Wire for Overhead Electrical Conductors
• Effective Date: 01-Nov-2008
• Referred By: ASTM B258-18 - Standard Specification for Standard Nominal Diameters and Cross-Sectional Areas of AWG Sizes of Solid Round Wires Used as Electrical Conductors
• Effective Date: 01-Nov-2008
• Referred By: ASTM B193-20 - Standard Test Method for Resistivity of Electrical Conductor Materials
• Effective Date: 01-Nov-2008

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:B957 −08
StandardSpecification for
Extra-High-Strength and Ultra-High-Strength Zinc-Coated
(Galvanized) Steel Core Wire for Overhead Electrical
Conductors
This standard is issued under the fixed designation B957; the number immediately following the designation indicates the year of
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. Scope 3. Terminology
1.1 This specification covers round, extra-high-strength and 3.1 Definitions of Terms Specific to This Standard:
ultra-high-strength, Class A zinc-coated (galvanized), steel 3.1.1 Lot, n—Unless otherwise specified in the contract or
core wire used for use in Overhead Electrical Conductors. order, a lot shall consist of all coils of wire of the same
diameter and unit lengths submitted for inspection at the same
1.2 This specification covers wire of diameter from 0.0500
time.
to 0.1900 in. inclusive or 1.27 to 4.82 mm inclusive.
3.1.2 Product Code, n—Defines product coating type, coat-
1.3 The values stated in either SI units or inch-pound units
ing class and strength grade.
are to be regarded separately as standard. The values stated in
• Extra High Strength Grade Zinc, ClassACoated, use Code
each system may not be exact equivalents; therefore, each
GA4.
system shall be used independently of the other. Combining
• Ultra High Strength Grade Zinc, Class A Coated, use Code
values from the two systems may result in non-conformance
GA5.
with the standard.
4. Ordering Information
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
4.1 Orders for material under this specification shall include
responsibility of the user of this standard to establish appro-
the following information:
priate safety and health practices and determine the applica-
4.1.1 Quantity of each size,
bility of regulatory limitations prior to use.
4.1.2 Wire diameter in inches or millimeter (Section 13),
4.1.3 Certification, if required (Section 18),
2. Referenced Documents
4.1.4 Test report, if required (Section 18), and
2.1 ASTM Standards: 4.1.5 Package size (Section 19).
A90/A90M Test Method for Weight [Mass] of Coating on
4.1.6 Strength Grade
Iron and Steel Articles with Zinc or Zinc-Alloy Coatings
5. Materials and Manufacture
A370 Test Methods and Definitions for Mechanical Testing
of Steel Products 5.1 The base metal shall be steel produced by the open-
A751 Test Methods, Practices, and Terminology for Chemi- hearth, electric-furnace, or basic-oxygen process.
cal Analysis of Steel Products
5.2 The wire shall be cold drawn and coated with zinc to
B6 Specification for Zinc
produce the desired properties.
B193 Test Method for Resistivity of Electrical Conductor
5.3 The slab zinc used for coating shall be high grade or
Materials
better, conforming to Specification B6.
E29 Practice for Using Significant Digits in Test Data to
Determine Conformance with Specifications
6. Chemical Composition
6.1 The steel shall conform to the requirements prescribed
This test method is under the jurisdiction of ASTM Committee B01 on in Table 1.
Electrical Conductors and is the direct responsibility of Subcommittee B01.05 on
6.2 Chemical analysis shall be conducted in accordance
Conductors of Ferrous Metals.
Current edition approved Nov. 1, 2008. Published December 2008. DOI: with Test Methods, Practices, and Terminology A751.
10.1520/B0957-08.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or 7. Tensile Test
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
7.1 The zinc-coated steel core wire shall conform to the
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. tensile and elongation requirements prescribed in Table 2,
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
B957−08
TABLE 1 Chemical Requirements TABLE 4 Grade 5 Ultra-High-Strength Tensile Requirements
Element Composition, % Specified Stress at Ultimate Elongation
Carbon 0.50 to 1.00 Diameter, 1% Extension, Tensile in 10 in.
Manganese 0.40 to 1.30 in. min, kpsi Strength, min %
Phosphorus, max 0.035 min, kpsi
Sulfur, max 0.045 0.0500 to 0.0899, incl 230 285 3.0
0.0900 to 0.1199, incl 225 275 3.0
Silicon 0.15 to 0.60
0.1200 to 0.1399, incl 220 270 3.5
0.1400 to 0.1900, incl 215 265 3.5
TABLE 2 Grade 4 Extra-High-Strength Tensile Requirements
Specified Stress at 1% Ultimate Tensile Elongation
TABLE 5 Grade 5 Ultra-High-Strength Tensile Requirements
Diameter, in. Extension, Strength, in 10 in.,
(Metric)
min, kpsi min, kpsi min %
0.0500 to 0.0899, incl 225 265 3.0
Specified Stress Ultimate Elongation
0.0900 to 0.1199, incl 220 260 3.0 Diameter, at 1% Tensile Strength, in 250 mm,
0.1200 to 0.1399, incl 215 255 3.5
mm Extension, min, MPa min %
0.1400 to 0.1900, incl 210 250 3.5 min, MPa
1.27 to 2.28, incl 1580 1965 3.0
2.29 to 3.04, incl 1550 1900 3.0
3.05 to 3.55, incl 1515 1860 3.5
Table 3, Table 4,or Table 5 depending on the strength grade
3.56 to 4.82, incl 1480 1825 3.5
and unit base ordered.
7.2 Tensile tests shall be conducted in accordance with Test
TABLE 6 Initial Settings for Determining Stress at 1% Extension
Methods and Definitions A370, using the initial settings for
Specified Initial Stress, Initial Setting
determining stress at 1 % extension given in Table 6 or Table
Diameter, kpsi of Extensometer,
7 of this specification.
in. in./in.
0.0500 to 0.0899, incl 18 0.0005 (0.05 % extension)
7.3 Test Specimens—The test specimens shall be free of
0.0900 to 0.1199, incl 36 0.0010 (0.10 % extension)
bendsorkinksotherthanthecurvatureresultingfromtheusual 0.1200 to 0.1900, incl 54 0.0015 (0.15 % extension)
coiling operations.Any hand straightening necessary to permit
insertion of the specimen in the jaws of the testing machine
TABLE 7 Initial Settings for Determining Stress at 1% Extension
shall be performed by drawing between wood blocks or by
(Metric)
some other equally satisfactory means.
Specified Initial Stress, Initial Setting
7.4 The nominal diameter requested shall be used to deter-
Diameter, MPa of Extensometer,
mm mm/mm
mine the applicable strength specification.
1.27 to 2.28, incl 124 0.0005 (0.05 % extension)
2.29 to 3.04, incl 248 0.0010 (0.10 % extension)
8. Wrap Test
3.05 to 4.82, incl 372 0.0015 (0.15 % extension)
8.1 The material, as represented by the test specimens, shall
not fracture when the galvanized wire is wrapped at a rate not
TABLE 8 Zinc Coating
exceeding 15 turns/min in a close helix of at least eight turns
around a cylindrical mandrel with a diameter equal to four Specified Diameter Area Density
of Coated Wire, of Zinc Coating, min of Uncoated
times the specified diameter of the wire under test, 65%.
in. Wire Surface,
oz/ft
9. Coating Test
0.0500 to 0.0599, incl 0.60
0.0600 to 0.0749, incl 0.65
9.1 The zinc-coated wire shall conform to the coating
0.0750 to 0.0899, incl 0.70
requirements prescribed in Table 8 or Table 9.
0.0900 to 0.1039, incl 0.75
0.1040 to 0.1199, incl 0.80
9.2 The coating test shall be conducted in accordance with
0.1200 to 0.1399, incl 0.85
Test Method A90/A90M. 0.1400 to 0.1799, incl 0.90
0.1800 to 0.1900, incl 1.00
10. Adherence of Coating Test
10.1 The zinc-coated wire shall be capable of being
wrapped in a close helix at a rate not exceeding 15 turns/min
aroundacylindricalmandrelhavingadiameterasprescribedin
Table 10 or Table 11, without cracking or flaking the zinc
coating to such an extent that any zinc can be removed by
TABLE 3 Grade 4 Extra-High-Strength Tensile Requirements
rubbing with the bare fingers.
(Metric)
Specified Stress at Ultimate Tensile Elongation
11. Joints
Diameter, 1% Extension, Strength, in 250 mm,
mm min, MPa min, MPa min %
11.1 No joints shall be made in the finished wire.
1.27 to 2.28, incl 1550 1825 3.0
2.29 to 3.04, incl 1515 1790 3.0
11.2 Joints may be made at any stage of processing prior to
3.05 to 3.55, incl 1480 1760 3.5
final cold drawing, by the electric butt-weld or flash-welding
3.56 to 4.82, incl 1450 1725 3.5
process.
B957−08
TABLE 9 Zinc Coating (Metric) TABLE 12 Permissible Variations in Diameter of Zinc-Coated
Steel Wire
Specified Diameter Area Density
of Coated Wire, of Zinc Coating, min of
NOTE 1—It is recognized that the surface of zinc coatings, particularly
mm Uncoated Wire Surface,
those produced by the hot-dip method of coating, are not perfectly smooth
g/m
and devoid of irregularities. If the tolerances shown in the table are rigidly
1.27 to 1.52, incl 183
applied to such irregularities that are inherent to the product, unjustified
1.53 to 1.90, incl 198
rejections of wire that would actually be satisfactory for use could occur.
1.91 to 2.28, incl 214
2.29 to 2
...