ASTM B452-22

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it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: B452 − 09 (Reapproved 2015) B452 − 22
Standard Specification for
Copper-Clad Steel Wire for Electronic Application
This standard is issued under the fixed designation B452; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope
1.1 This specification covers bare round copper-clad steel wire for electronic application.
1.2 Four classes of copper-clad steel wire are covered as follows:
1.2.1 Class 30HS—Nominal 30 % conductivity high-strength hard-drawn,
1.2.2 Class 30A—30HS-A—Nominal 30 % conductivity high-strength annealed,
1.2.3 Class 40HS—Nominal 40 % conductivity high-strength hard-drawn, and
1.2.4 Class 40A—40HS-A—Nominal 40 % conductivity high-strength annealed.
1.3 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are in SI units.
1.4 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.
2. Referenced Documents
2.1 The following documents of the issue in effect on the date of material purchase form a part of this specification to the extent
referenced herein:
2.2 ASTM Standards:
B193 Test Method for Resistivity of Electrical Conductor Materials
B258 Specification for Standard Nominal Diameters and Cross-Sectional Areas of AWG Sizes of Solid Round Wires Used as
Electrical Conductors
2.3 National Institute of Standards and Technology:NIST Documents:
NBS Handbook 100—Copper Wire Tables
This specification is under the jurisdiction of ASTM Committee B01 on Electrical Conductors and is the direct responsibility of Subcommittee B01.06 on Bi-Metallic
Conductors.
Current edition approved April 1, 2015May 1, 2022. Published April 2015May 2022. Originally approved in 1967. Last previous edition approved in 20092015 as
B452 – 09.B452 – 09 (2015). DOI: 10.1520/B0452-09R15.10.1520/B0452-22.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Available from National Institute of Standards and Technology (NIST), 100 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
B452 − 22
3. Ordering Information
3.1 Orders for material under this specification shall include the following information:
3.1.1 Quantity of each size and class,
3.1.2 Wire size, diameter in inches (see 5.3 and Table 1),
3.1.3 Class of wire (see 1.2 and Table 1),
3.1.4 Packaging and shipping (Section 10),
3.1.5 If inspection is required (see 6.3.3), and
3.1.6 Place of inspection (see 6.1).
4. Material
4.1 The wire shall consist of a core of homogeneous open-hearth, electric-furnace, or basic-oxygen high-strength steel with a
continuous outer cladding of copper thoroughly bonded to the core throughout and shall be of such quality as to meet the
requirements of this specification (Note 1).
TABLE 1 Tensile and Elongation Requirements
Elongation, min.
Tensile Strength, min
Diameter Cross-Sectional Area at 20°C20 °C % in 10 in.
psi (kgf/mm )
(250 mm)
Class Class
Class 30HS, Class 30A, Class 40HS, Class 40A, 30HS 30A30HS-A
2 2
in. mm cmil in. mm
min30HS min30HS-A min40HS min40HS-A and and
40HS 40A40HS-A
0.0720 1.83 5180 0.00407 2.63 127 000 (89.3) 50 000 (35.2) 110 000 (77.3) 45 000 (31.6) 1.5 15
0.0641 1.63 4110 0.00323 2.08 127 000 (89.3) 50 000 (35.2) 110 000 (77.3) 45 000 (31.6) 1.5 15
0.0571 1.45 3260 0.00256 1.65 127 000 (89.3) 50 000 (35.2) 110 000 (77.3) 45 000 (31.6) 1.5 15
0.0508 1.29 2580 0.00203 1.31 127 000 (89.3) 50 000 (35.2) 110 000 (77.3) 45 000 (31.6) 1.5 15
0.0453 1.15 2050 0.00161 1.04 127 000 (89.3) 50 000 (35.2) 110 000 (77.3) 45 000 (31.6) 1.5 15
0.0403 1.02 1620 0.00128 0.823 127 000 (89.3) 50 000 (35.2) 110 000 (77.3) 45 000 (31.6) 1.0 15
0.0359 0.912 1290 0.00101 0.653 127 000 (89.3) 50 000 (35.2) 110 000 (77.3) 45 000 (31.6) 1.0 15
0.0320 0.813 1020 0.000804 0.519 127 000 (89.3) 50 000 (35.2) 110 000 (77.3) 45 000 (31.6) 1.0 15
0.0285 0.724 812 0.000638 0.412 127 000 (89.3) 55 000 (38.7) 110 000 (77.3) 50 000 (35.2) 1.0 15
0.0253 0.643 640 0.000503 0.324 127 000 (89.3) 55 000 (38.7) 110 000 (77.3) 50 000 (35.2) 1.0 15
0.0226 0.574 511 0.000401 0.259 127 000 (89.3) 55 000 (38.7) 110 000 (77.3) 50 000 (35.2) 1.0 15
0.0201 0.511 404 0.00317 0.205 127 000 (89.3) 55 000 (38.7) 110 000 (77.3) 50 000 (35.2) 1.0 10
0.0179 0.455 320 0.000252 0.162 127 000 (89.3) 55 000 (38.7) 110 000 (77.3) 50 000 (35.2) 1.0 10
0.0159 0.404 253 0.000199 0.128 127 000 (89.3) 55 000 (38.7) 110 000 (77.3) 50 000 (35.2) 1.0 10
0.0142 0.361 202 0.000158 0.102 127 000 (89.3) 55 000 (38.7) 110 000 (77.3) 50 000 (35.2) 1.0 10
0.0126 0.320 159 0.000125 0.0804 127 000 (89.3) 55 000 (38.7) 110 000 (77.3) 50 000 (35.2) 1.0 10
0.0113 0.287 128 0.000100 0.0647 127 000 (89.3) 55 000 (38.7) 110 000 (77.3) 50 000 (35.2) 1.0 10
0.0100 0.254 100 0.0000785 0.0507 127 000 (89.3) 55 000 (38.7) 110 000 (77.3) 50 000 (35.2) 1.0 10
0.0089 0.226 79.2 0.0000622 0.0401 127 000 (89.3) 55 000 (38.7) 110 000 (77.3) 50 000 (35.2) 1.0 10
0.0080 0.203 64.0 0.0000503 0.0324 127 000 (89.3) 55 000 (38.7) 110 000 (77.3) 50 000 (35.2) 1.0 10
0.0071 0.180 50.4 0.0000396 0.0255 127 000 (89.3) 55 000 (38.7) 110 000 (77.3) 50 000 (35.2) 1.0 10
0.0063 0.160 39.7 0.0000312 0.0201 127 000 (89.3) 55 000 (38.7) 110 000 (77.3) 50 000 (35.2) 1.0 10
0.0056 0.142 31.4 0.0000246 0.0159 127 000 (89.3) 55 000 (38.7) 110 000 (77.3) 50 000 (35.2) 1.0 10
0.0050 0.127 25.0 0.0000196 0.0127 127 000 (89.3) 55 000 (38.7) 110 000 (77.3) 50 000 (35.2) 1.0 10
0.0045 0.114 20.2 0.0000159 0.0103 127 000 (89.3) 55 000 (38.7) 110 000 (77.3) 50 000 (35.2) 1.0 10
0.0040 0.102 16.0 0.0000126 0.00811 127 000 (89.3) 55 000 (38.7) 110 000 (77.3) 50 000 (35.2) 1.0 10
0.0035 0.089 12.2 0.00000962 0.00621 127 000 (89.3) 55 000 (38.7) 110 000 (77.3) 50 000 (35.2) 1.0 10
0.0031 0.079 9.61 0.00000755 0.00487 127 000 (89.3) 55 000 (38.7) 110 000 (77.3) 50 000 (35.2) 1.0 10
B452 − 22
NOTE 1—The copper-clad steel wire provides a high-strength conductor for use in wire and cable where greater strength is required and a lower
conductivity can be tolerated. At high frequencies the reduced conductivity is less pronounced due to concentration of the current in the outer periphery
of the wire. Minimum thickness of 6 % and 10 % of the radius for 30 and 40 % conductivity material, respectively, has been established to facilitate the
inspection of thickness on fine wires.
NOTE 1—The copper-clad steel wire provides a high-strength conductor for use in wire and cable where greater strength is required and a lower
conductivity can be tolerated. At high frequencies the reduced conductivity is less pronounced due to concentration of the current in the outer periphery
of the wire. Minimum thickness of 6 % and 10 % of the radius for 30 and 40 % conductivity material, respectively, has been established to facilitate the
inspection of thickness on fine wires.
5. General Requirements
5.1 Tensile Strength and Elongation—The copper-clad steel wire shall conform to the tensile strength and elongation requirements
of Table 1. For intermediate sizes not listed in Table 1, the elongation requirements of the next smaller size shall apply; in the case
of tensile strength, the requirements of the next larger size shall apply.
5.2 Resistivity—The electrical resistivity at a temperature of 20°C20 °C shall not exceed the values prescribed in Table 2. See Note
2 for calculating electrical resistance.
NOTE 2—Relationships which may be useful in connection with the values of electrical resistivity prescribed in this specification are shown in Table 3.
Resistivity units are based on the International Annealed Copper Standard (IACS) adopted by IEC in 1913, which is ⁄58 Ω·mm /m at 20°C20 °C for 100 %
2 2
conductivity. The value of 0.017241 Ω·mm /m and the value of 0.15328 Ω·g/m at 20°C20 °C are respectively the international equivalent of volume and
weight resistivity of annealed copper equal to 100 % conductivity. The latter term means that a copper wire 1 in. in length and weighing 1 g would have
a resistance of 0.15328 Ω. This is equivalent to a resistivity value of 875.20Ω· 875.20 Ω·lb lb/mile⁄mile , which signifies the resistance of a copper wire
1 mile in length weighing 1 lb. 1 lb. It is also equivalent, for example, to 1.7241 μΩ/cm of length of a copper bar 1 cm in cross section. A complete
discussion of this subject is contained in NBS Handbook 100. The use of five significant figures in expressing 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 units to another.
5.3 Dimensions and Permissible Variations—The wire sizes shall be expressed as the diameter of the wire in decimal fractions
of an inch to the nearest 0.0001 in. (0.003 mm) (Note 3). For diameters under 0.0100 in. (0.254 mm), the wire shall not vary from
the specified diameter by more than 60.0001 in. (0.003 mm) and for diameters of 0.0100 in. (0.254 mm) and over, the wire shall
not vary from the specified diameter by more than 61 %, expressed to the nearest 0.0001 in. (0.003 mm).
NOTE 3—The values of the wire diameters in Table 1 are given to the nearest 0.0001 in. (0.003 mm) and correspond to the standard sizes given in
Specification B258. The use of gagegauge numbers to specify wire sizes is not recognized in this specification because of the possibility of confusion.
An excellent discussion of wire gagesgauges and related subjects is contained in NBS Handbook 100.
5.4 Adhesion and Other Defects—The copper-clad steel wire, when tested in accordance with 7.4, shall not reveal any seams, pits,
slivers, or other imperfection of sufficient magnitude to indicate inherent defects or imperfections. Examination of the wire at the
break with the unaided eye (normal spectacles excepted) shall show no separation of copper from the steel.
5.5 Joints—Necessary joints in the wire and rods prior to final drawing shall be made in accordance with good commercial
practice. The finished wire shall contain no joints or splices made at finished size.
5.6 Finish—The wire shall be free from copper discontinuities and all imperfections not consistent with good commercial practice
(see 7.5).
5.7 Copper Thickness—The average copper thickness must be sufficient to meet the maximum resistivity values stated in Table
2. The minimum copper thickness at any point around the circumference shall be not less than the following:
TABLE 2 Resistivity, max, at 20°C
Class of Wire Ω·mm /m
30HS and 30A 0.05862 (0.058616)
40HS and 40A 0.04397 (0.043970)
TABLE 2 Resistivity, max, at 20 °C
Class of Wire Ω·mm /m
30HS and 30HS-A 0.05862 (0.058616)
40HS and 40HS-A 0.04397 (0.043970)
B452 − 22
TABLE 3 Equivalent Resistivity Values
IACS Resistivity Equivalents at 20°C
Volume Conduc-
Class Volume Mass
tivity at 20°C, %
2 2 2
Ω·mm /m Ω·cmil/ft μΩ·in. μΩ·cm Ω·lb/ mile Ω·g/m
40A and 40HS 39.210 0.043970 26.45 1.7312 4.3970 2046.3 0.35836
30A and 30HS 29.413 0.058616 35.26 2.3078 5.8616 2727.8 0.47772
TABLE 3 Equivalent Resistivity Values
IACS Resistivity Equivalents at 20 °C
Volume Conduc-
Class Volume Mass
tivity at 20 °C, %
2 2 2
Ω·mm /m Ω·cmil/ft μΩ·in. μΩ·cm Ω·lb/mile Ω·g/m
40HS-A and 40HS 39.210 0.043970 26.45 1.7312 4.3970 2046.3 0.35836
30HS-A and 30HS 29.413 0.058616 35.26 2.3078 5.8616 2727.8 0.47772
5.7.1 The 30 % conductivity wire shall have a minimum thickness of not less than 6 % of the wire radius.
5.7.2 The 40 % conductivity wire shall have a minimum thickness of not less than 10 % of the wire radius (see 7.6 and Note 3).
6. Inspection
6.1 General—All tests and inspections shall be made at the place of manufacture unless otherwise agreed upon between the
manufacturer and the purchaser at the time of the purchase. The manufacturer shall afford the inspector representing the purchaser
all reasonable facilities to satisfy him that the material is being furnished in accordan
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