ASTM B910/B910M-07(2023)
(Specification)Standard Specification for Annealed Copper-Clad Steel Wire
Standard Specification for Annealed Copper-Clad Steel Wire
ABSTRACT
This specification covers annealed bare round copper-clad steel wire for the following applications: electrical, electronic, grounding, telecommunications, and other applications. Four types of copper-clad steel wires according to their electrical conductivities are included. The wire shall consist of a core of homogeneous open-hearth, electric-furnace, or basic-oxygen steel with a continuous outer cladding of copper thoroughly bonded to the core throughout. The copper-clad steel wire shall conform to the specified requirements for: tensile strength, elongation, dimension (diameter), adhesion and surface defects, joints, finish, copper thickness, density, and electrical resistivity. Methods for measurement, inspection, and testing such as torsion (twist) test are detailed.
SCOPE
1.1 This specification covers bare round copper-clad steel for the following applications: electrical, electronic, grounding, telecommunications, and other applications.
1.2 Four conductivities are covered as follows: 21 %, 30 %, 40 %, and 70 %.
1.3 Temper is designated as annealed.
1.4 The values stated in inch-pound or SI units are to be regarded separately as the standard. Each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the specification. For conductor sizes designated by AWG, the requirements in SI units have been numerically converted from corresponding values stated or derived in inch-pound units. For conductor sizes designated by SI units only, the requirements are stated or derived in SI units.
1.5 The following precautionary statement pertains to the test method portion only, Section 7, 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.
1.6 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.
General Information
Relations
Standards Content (Sample)
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.
Designation: B910/B910M − 07 (Reapproved 2023)
Standard Specification for
Annealed Copper-Clad Steel Wire
This standard is issued under the fixed designation B910/B910M; 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 2.2 ASTM Standards:
B193 Test Method for Resistivity of Electrical Conductor
1.1 This specification covers bare round copper-clad steel
Materials
for the following applications: electrical, electronic, grounding,
B258 Specification for Standard Nominal Diameters and
telecommunications, and other applications.
Cross-Sectional Areas of AWG Sizes of Solid Round
1.2 Four conductivities are covered as follows: 21 %, 30 %, Wires Used as Electrical Conductors
40 %, and 70 %.
2.3 NIST Document:
NBS Handbook 100 —Copper Wire Tables
1.3 Temper is designated as annealed.
3. Ordering Information
1.4 The values stated in inch-pound or SI units are to be
regarded separately as the standard. Each system shall be used
3.1 Orders for material under this specification shall include
independently of the other. Combining values from the two
the following information:
systems may result in nonconformance with the specification.
3.1.1 Quantity of each size;
For conductor sizes designated by AWG, the requirements in SI
3.1.2 Wire size: diameter in inches (see 5.2);
units have been numerically converted from corresponding
3.1.3 Conductivity (see Table 1);
values stated or derived in inch-pound units. For conductor
3.1.4 Wire to be used for redraw or not;
sizes designated by SI units only, the requirements are stated or
3.1.5 Packaging and shipping (see 10); and
derived in SI units.
3.1.6 Place of inspection (see 6.1).
1.5 The following precautionary statement pertains to the
4. Material
test method portion only, Section 7, of this specification: This
standard does not purport to address all of the safety concerns, 4.1 The wire shall consist of a core of homogeneous
if any associated with its use. It is the responsibility of the user open-hearth, electric-furnace, or basic-oxygen steel with a
of this standard to establish appropriate safety, health, and continuous outer cladding of copper thoroughly bonded to the
environmental practices and determine the applicability of core throughout and shall be of such quality as to meet the
regulatory limitations prior to use. requirements of this specification.
1.6 This international standard was developed in accor-
5. General Requirements
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the 5.1 Tensile Strength and Elongation—The copper-clad steel
Development of International Standards, Guides and Recom- wire shall conform to the tensile strength requirements of Table
mendations issued by the World Trade Organization Technical 2. Because there are many carbon steel and copper thickness
combinations available, the desired tensile strength should be
Barriers to Trade (TBT) Committee.
agreed upon between the purchaser and manufacturer prior to
placing an order. The elongation shall be 15.0 % minimum for
2. Referenced Documents
all diameters listed in 5.2.
2.1 The following documents of the issue in effect on the
5.2 Dimensions—The wire size range for this specification
date of material purchase form a part of this specification to the
shall be from 0.0253 in. (0.643 mm) to 0.2294 in. (5.827 mm)
extent referenced herein:
diameter (see Note 1).
1 2
This specification is under the jurisdiction of ASTM Committee B01 on For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Electrical Conductors and is the direct responsibility of Subcommittee B01.06 on contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Bi-Metallic Conductors. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Oct. 1, 2023. Published October 2023. Originally the ASTM website.
approved in 2000. Last previous edition approved in 2018 as B910/B910M – 07 Available from National Institute of Standards and Technology (NIST), 100
(2018). DOI: 10.1520/B0910_B0910M-07R23. Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http://www.nist.gov.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
B910/B910M − 07 (2023)
TABLE 1 Density (nom.) and Resistivity, (max.), at 20 °C (Nominal Standard (IACS) adopted by IEC in 1913, which is ⁄58 ohm mm /m at
Conductivity, Minimum Conductivity, and Nominal Density for
20 °C for 100 % conductivity. The value of 0.017241 ohm mm /m and the
Reference Only) value of 0.15328 ohm g/m at 20 °C are, respectively, the international
equivalent of volume and weight resistivity of annealed copper equal to
Maximum Resistivity
100 % conductivity. The latter term means that a copper wire 1 in. in
Nominal Density at 20 °C
Nominal Minimum
length and weighing 1 g would have a resistance of 0.15328 ohm. This is
Conductivity (ohm Conductivity
equivalent to a resistivity value of 875.20 ohm lb/mile , which signifies
3 3 2
(% IACS) lb/in. (g/cm ) Ohm cmil/ft mm /m) (% IACS)
the resistance of a copper wire 1 mile in length weighing 1 lb. It is also
21 0.2885 (7.99) 54.58 (0.0907) 19.00
equivalent, for example, to 1.7241 ohm/cm of length of a copper bar 1 cm
30 0.2944 (8.15) 35.26 (0.0586) 29.41
in cross section. A complete discussion of this subject is contained in
40 0.2975 (8.24) 26.45 (0.0440) 39.21
NBS Handbook 100. The use of five significant figures in expressing
70 0.3098 (8.58) 15.96 (0.0265) 65.00
resistivity does not imply the need for greater accuracy of measurement
than that specified in Test Method B193. The use of five significant figures
is required for complete reversible conversion from one set of resistivity
TABLE 2 Tensile and Minimum Copper Thickness (Conductivity
units to another.
and Nominal Copper Thickness for Reference Only)
Minimum Tensile Minimum Copper Nominal Copper 6. Inspection
Nominal
Strength Thickness Thickness
Conductivity
6.1 General—All tests and inspections shall be made at the
(% IACS) psi (N/mm ) (% of Diameter) (% of Diameter)
place of manufacture unless otherwise agreed upon between
21 50 000 (345) 1.5 3
the manufacturer and the purchaser at the time of the purchase.
30 45 000 (310) 3.0 7
40 40 000 (276) 5.0 9
The manufacturer shall afford the inspector representing the
70 35 000 (241) 15.0 20
purchaser all reasonable facilities to satisfy him that the
material is being furnished in accordance with this specifica-
tion (Note 3).
5.2.1 Permissible Variations—The wire sizes shall meet the
NOTE 3—Cumulative results secured on the product of a single
following tolerances:
manufacturer, indicating continued conformance to the criteria, are
5.2.1.1 For diameters 0.1000 in. (2.54 mm) and over, the
necessary to ensure an over-all product meeting the requirements of this
specification. The sample sizes and conformance criteria given for the
wire shall not vary from the specified diameter by more than 6
various characteristics are applicable only to lots produced under these
1 ⁄2 %, expressed to the nearest 0.0001 in. (0.003 mm).
conditions.
5.2.1.2 For diameters under 0.1000 in. (2.54 mm) and above
6.1.1 Unless otherwise agreed by the manufacturer and the
0.0253 in. (0.643 mm), the wire shall not vary from the
purchaser, conformance of the wire to the various requirements
specified diameter by more than 61 %, expressed to the
listed in Section 5 shall be determined on samples taken from
nearest 0.0001 in. (0.003 mm).
each lot of wire presented for acceptance.
NOTE 1—The values of the wire diameters in 5.2 are given to the nearest
6.1.2 The manufacturer shall, if requested prior to
0.0001 in. (0.003 mm) and correspond to the standard sizes given in
inspection, certify that all wire in the lot was made under such
Specification B258. The use of gauge numbers to specify wire sizes is not
conditions that the product as a whole conforms to the
recognized in this specification because of the possibility of confusion. An
excellent discussion of wire gauges and related subjects is contained in requirements of this specification as determined by regularly
NBS Handbook 100.
made and recorded tests.
5.3 Adhesion and Surface Defects—The copper-clad steel
6.2 Definitions:
wire, when tested in accordance with 7.4, shall not reveal any
6.2.1 lot—any amount of wire of one class and size pre-
seams, pits, slivers, or other imperfection of sufficient magni-
sented for acceptance at one time, such amount, however, is not
tude to indicate inherent defects or imperfections. Examination
to exceed 40 000 lb (18 144 kg) (Note 4).
of the wire at the break with the unaided eye (normal spectacles
NOTE 4—A lot should comprise material taken from a product regularly
excepted) shall show no separation of copper from the steel.
meeting the requirements of this specification. Inspection of individual
5.4 Joints—Necessary joints in the wire and rods prior to
lots of less than 500 lb (230 kg) of wire cannot be justified economically.
For small lots of 500 lb (230 kg) or less, the purchaser may agree to the
final drawing shall be made in accordance with good commer-
manufacturer’s regular inspection of the product as a whole as evidence of
cial practice. The finished wire shall contain no joints or splices
acceptability of such small lots.
made at finished size.
6.2.2 sample—a quantity of production units (coils, reels,
5.5 Finish—The wire shall be free from copper discontinui-
and so forth) selected at random from the lot for the purpose of
ties and all imperfections not consistent with good commercial
determining conformance of the lot to the requirements of this
practice (see 7.5).
specification.
5.6 Copper Thickness—The minimum copper thickness due
6.2.3 specimen—a length of wire removed for test purposes
to eccentricity shall not be less than shown in Table 2.
from any individual production unit of the sample.
5.7 Resistivity—The electrical resistivity at a temperature of
6.3 Sample Size—The number of production units in a
20 °C shall not exceed the values prescribed in Table 1. See
sample (see Note 3) shall be as follows:
Note 2 for cal
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