ASTM B902/B902M-13(2018)

Standard Specification for Compressed Round Stranded Copper Conductors, Hard, Medium-Hard, or Soft Using Single Input Wire Construction

ABSTRACT
This specification covers stranded conductors made from round copper wires, either uncoated or coated with tin, lead, or lead alloy for general use in insulated conductor assemblies for electrical purposes. These conductors shall be composed of one or more roller shaped or die closed layers of helically laid wires using the single input wire. For stranded conductors, the direction of lay of the outer layer shall be leeft hand and may be reversed or unidirectional/unilay in successive layers. Test for the physical and electrical properties of wires composing conductors made from hard-drawn or medium-hard-drawn wires, uncoated or coated, shall be made before but not after stranding. For the purpose of calculating mass, cross sections, and so forth, the density of the copper shall be taken. The mass and electrical resistance of a unit length of stranded unsealed conductor are a function of the lenght of lay shall be calculated.
SCOPE
1.1 This specification covers stranded conductors made from round copper wires, either uncoated or coated with tin, lead, or lead alloy for general use in insulated conductor assemblies for electrical purposes. These conductors shall be composed of one or more roller shaped or die closed layers of helically laid wires using the single input wire (SIW) methodology. (see Note 1 and Explanatory Note 1)
Note 1: Sealed conductors which are intended to prevent longitudinal water propagation and are further covered/insulated, are also permitted within the guidelines of this specification.  
1.2 The values stated in inch-pound or SI units are to be regarded separately as standard. The values in each system are not exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the specification.  
1.2.1 For density, resistivity, and temperature, the values stated in SI units are to be regarded as standard.  
1.3 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

• Status: Published
• Publication Date: 30-Sep-2018
• ICS: 29.060.10 - Wires
• Technical Committee: B01 - Electrical Conductors
• Drafting Committee: B01.04 - Conductors of Copper and Copper Alloys

Relations

• Replaces: ASTM B902/B902M-13e1 - Standard Specification for Compressed Round Stranded Copper Conductors, Hard, Medium-Hard, or Soft Using Single Input Wire Construction
• Effective Date: 01-Oct-2018
• Refers: ASTM B3-13(2024) - Standard Specification for Soft or Annealed Copper Wire
• Effective Date: 01-Apr-2024
• Refers: ASTM B33-10(2020)e1 - Standard Specification for Tin-Coated Soft or Annealed Copper Wire for Electrical Purposes
• Effective Date: 01-Jan-2020
• Refers: ASTM B3-13(2018) - Standard Specification for Soft or Annealed Copper Wire
• Effective Date: 01-Oct-2018
• Refers: ASTM B1-13(2018) - Standard Specification for Hard-Drawn Copper Wire
• Effective Date: 01-Oct-2018
• Refers: ASTM B2-13(2018) - Standard Specification for Medium-Hard-Drawn Copper Wire
• Effective Date: 01-Oct-2018
• Refers: ASTM B354-16 - Standard Terminology Relating to Uninsulated Metallic Electrical Conductors
• Effective Date: 01-Sep-2016
• Refers: ASTM B193-16 - Standard Test Method for Resistivity of Electrical Conductor Materials
• Effective Date: 01-Apr-2016
• Refers: ASTM B33-10(2014) - Standard Specification for Tin-Coated Soft or Annealed Copper Wire for Electrical Purposes
• Effective Date: 01-Sep-2014
• Refers: ASTM B193-02(2014) - Standard Test Method for Resistivity of Electrical Conductor Materials
• Effective Date: 01-Apr-2014
• Refers: ASTM B2-13 - Standard Specification for Medium-Hard-Drawn Copper Wire
• Effective Date: 01-Oct-2013
• Refers: ASTM B1-13 - Standard Specification for Hard-Drawn Copper Wire
• Effective Date: 01-Oct-2013
• Refers: ASTM B3-13 - Standard Specification for Soft or Annealed Copper Wire
• Effective Date: 01-Oct-2013
• Refers: ASTM B354-12 - Standard Terminology Relating to Uninsulated Metallic Electrical Conductors
• Effective Date: 01-Dec-2012
• Refers: ASTM B2-12 - Standard Specification for Medium-Hard-Drawn Copper Wire
• Effective Date: 15-Nov-2012

Overview

ASTM B902/B902M-13(2018) is the standard specification for compressed round stranded copper conductors, which may be hard, medium-hard, or soft, produced using single input wire (SIW) construction. Developed by ASTM International, this specification covers stranded copper conductors that are either uncoated or coated (with tin, lead, or lead alloy). It is primarily intended for general use in insulated conductor assemblies for electrical applications.

This standard defines essential requirements for the construction, physical and electrical properties, and testing procedures for SIW compressed stranded copper conductors. Both inch-pound and metric (SI) units are recognized, with specific guidance on when each system applies. The document aligns with international standardization principles, supporting consistency and reliability in electrical conductor manufacturing and procurement globally.

Key Topics

• Scope and Coverage: Specifies requirements for round, compressed, stranded copper conductors made with SIW construction, including both coated and uncoated wires.
• Wire Types: Covers various tempers (hard, medium-hard, and soft) and coatings (none, tin, lead, or lead alloy) appropriate for different electrical environments.
• Construction Requirements:
  • One or more layers of helically laid wires, roller-shaped or die-closed.
  • Direction of lay for the outer layer is typically left hand; additional layers may be reversed or unidirectional as needed.
• Testing and Quality Assurance:
  • Physical and electrical tests must be conducted on the component wires before stranding.
  • Includes elongation, tensile, and resistivity tests, with clear guidance on permissible variances after stranding.
• Dimensional and Electrical Properties:
  • Tables provide nominal values for conductor diameter, mass, and resistance per unit length.
  • Maximum allowable variations and calculation methods for resistance, cross-sectional area, and mass.
• Packaging and Marking:
  • Detailed marking for packaging, including size, length, coating, and order information to ensure traceability and compliance.

Applications

Compressed round stranded copper conductors manufactured under ASTM B902/B902M-13(2018) are widely used in the electrical industry, particularly for:

• Insulated conductor assemblies: As the base conductor in cables that are subsequently covered or insulated for use in various power, control, and signal transmission installations.
• Utility and industrial wiring: For transmission and distribution of electrical power due to copper’s high conductivity and mechanical strength.
• Equipment installations: Where a balance of flexibility, strength, and reliable electrical performance is needed, such as panels, switchgears, and large-scale industrial facilities.
• Custom and specialty cabling: Where specific requirements for strand lay, conductor size, or coating must be met for unique projects or challenging environments.

The standard's versatility supports a broad spectrum of electrical builders and equipment manufacturers who require consistent material performance and global compliance.

Related Standards

Several other ASTM standards and technical documents are closely linked to ASTM B902/B902M-13(2018), providing reference specifications for source materials and test methods:

• ASTM B1: Specification for Hard-Drawn Copper Wire
• ASTM B2: Specification for Medium-Hard-Drawn Copper Wire
• ASTM B3: Specification for Soft or Annealed Copper Wire
• ASTM B33: Specification for Tin-Coated Soft or Annealed Copper Wire
• ASTM B189: Specification for Lead-Coated and Lead-Alloy-Coated Soft Copper Wire
• ASTM B246: Specification for Tinned Hard-Drawn and Medium-Hard-Drawn Copper Wire
• ASTM B193: Test Method for Resistivity of Electrical Conductor Materials
• ASTM B263: Test Method for Determination of Cross-Sectional Area of Stranded Conductors
• ASTM B354: Terminology Relating to Uninsulated Metallic Electrical Conductors

For calculations and additional guidelines, NBS Handbook 100 - Copper Wire Tables is also referenced. Adhering to these related standards ensures proper material selection, testing, and overall compatibility in the manufacturing of copper electrical conductors.

Keywords: ASTM B902, SIW compressed copper conductor, stranded copper conductor, electrical conductor standards, copper wire, single input wire, tinned copper, lead-coated copper, conductor resistance, conductor mass, industrial electrical wiring, ASTM standards.

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:B902/B902M −13 (Reapproved 2018)
Standard Specification for
Compressed Round Stranded Copper Conductors, Hard,
Medium-Hard, or Soft Using Single Input Wire Construction
This standard is issued under the fixed designation B902/B902M; 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 B189 Specification for Lead-Coated and Lead-Alloy-Coated
Soft Copper Wire for Electrical Purposes
1.1 This specification covers stranded conductors made
B193 Test Method for Resistivity of Electrical Conductor
from round copper wires, either uncoated or coated with tin,
Materials
lead, or lead alloy for general use in insulated conductor
B246 Specification for Tinned Hard-Drawn and Medium-
assemblies for electrical purposes. These conductors shall be
Hard-Drawn Copper Wire for Electrical Purposes
composed of one or more roller shaped or die closed layers of
B263 Test Method for Determination of Cross-Sectional
helically laid wires using the single input wire (SIW) method-
Area of Stranded Conductors
ology. (see Note 1 and Explanatory Note 1)
B354 Terminology Relating to Uninsulated Metallic Electri-
NOTE 1—Sealed conductors which are intended to prevent longitudinal
cal Conductors
water propagation and are further covered/insulated, are also permitted
2.2 Other Standard:
within the guidelines of this specification.
NBS Handbook 100 —Copper Wire Tables
1.2 The values stated in inch-pound or SI units are to be
3. Classification
regarded separately as standard. The values in each system are
not exact equivalents; therefore, each system shall be used
3.1 The conductors described in this specification are in-
independently of the other. Combining values from the two
tendedforsubsequentinsulationorcovering.Theclassification
systems may result in nonconformance with the specification.
of these conductors is SIW compressed.
1.2.1 For density, resistivity, and temperature, the values
4. Ordering Information
stated in SI units are to be regarded as standard.
1.3 This international standard was developed in accor- 4.1 Orders for material under this specification shall include
dance with internationally recognized principles on standard- the following information:
ization established in the Decision on Principles for the
4.1.1 Quantity of each size,
Development of International Standards, Guides and Recom- 4.1.2 Conductorsize:circular-milareaorAWG(seeSection
mendations issued by the World Trade Organization Technical
7),
Barriers to Trade (TBT) Committee. 4.1.3 Class: SIW compressed (see 1.2 and Table 1),
4.1.4 Temper (see 5.3),
2. Referenced Documents
4.1.5 Whether coated or uncoated; if coated (see 5.1 and
5.2).
2.1 ASTM Standards:
4.1.6 Details of special-purpose lays, if required (see 7.3).
B1 Specification for Hard-Drawn Copper Wire
4.1.7 When physical tests shall be made (see Sections 9 and
B2 Specification for Medium-Hard-Drawn Copper Wire
10).
B3 Specification for Soft or Annealed Copper Wire
4.1.8 Package size (see 16.1).
B33 Specification for Tin-Coated Soft or Annealed Copper
4.1.9 Lagging, if required (see 16.2).
Wire for Electrical Purposes
4.1.10 Special package marking, if required (see Section
16.3), and
This specification is under the jurisdiction of ASTM Committee B01 of
4.1.11 Place of inspection (see Section 15).
Electrical Conductors and is the direct responsibility of Subcommittee B01.04 on
Conductors of Copper and Copper Alloys.
5. Requirements for Wires
Current edition approved Oct. 1, 2018. Published October 2018. Originally
ɛ1
5.1 The purchaser shall designate the type of wire and the
approved in 2000. Last previous edition approved in 2013 as B902/B902M – 13 .
DOI: 10.1520/B0902_B0902M-13R18.
kind of coating, if any, to be used in the conductor.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on Available from National Technical Information Service (NTIS), 5301 Shawnee
the ASTM website. Rd., Alexandria, VA 22312, http://www.ntis.gov.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
B902/B902M−13 (2018)
TABLE 1 Construction Requirements of Compressed Round SIW Standard Copper Conductors
Compressed Strand Dimensions
Conductor Size Nominal Nominal
Diameter Diameter
of SIW of SIW
Minimum Compressed Compressed
Number of Conductor, Conductor, Mass DC Resistance at 20°C
cmils AWG mm Wires in. mm. lb/1000ft kg/km Ω/1000ft Ω/km
5 000 000 2534 217 2.424 61.57 15890 23649 0.00218 0.00715
4 500 000 2280 217 2.300 58.41 14300 21283 0.00242 0.00794
4 000 000 2027 217 2.168 55.07 12590 18738 0.00270 0.00886
3 500 000 1773 169 2.028 51.51 11020 16401 0.00308 0.01010
3 000 000 1520 169 1.878 47.69 9353 13920 0.00365 0.01197
2 500 000 1267 127 1.714 43.54 7794 11600 0.00428 0.01404
2 000 000 1013 127 1.533 38.94 6175 9190 0.00529 0.01735
1 900 000 962.7 127 1.494 37.95 5866 8730 0.00557 0.01827
1 800 000 912.1 127 1.454 36.93 5558 8272 0.00588 0.01929
1 750 000 886.7 127 1.434 36.42 5403 8041 0.00604 0.01981
1 700 000 861.4 127 1.413 35.89 5249 7812 0.00622 0.02040
1 600 000 810.7 127 1.371 34.82 4940 7352 0.00661 0.02168
1 500 000 760.1 90 1.327 33.71 4631 6892 0.00705 0.02312
1 400 000 709.4 90 1.282 32.56 4323 6434 0.00756 0.02480
1 300 000 658.7 90 1.236 31.39 4014 5974 0.00814 0.02670
1 250 000 633.4 90 1.212 30.78 3859 5743 0.00847 0.02778
1 200 000 608.0 90 1.187 30.15 3705 5514 0.00882 0.02893
1 100 000 557.4 90 1.137 28.88 3396 5054 0.00962 0.03155
1 000 000 506.7 53 1.084 27.53 3088 4596 0.0106 0.0348
900 000 456.0 53 1.028 26.11 2779 4136 0.0118 0.3087
800 000 405.4 53 0.969 24.61 2470 3676 0.0132 0.0433
750 000 380.0 53 0.939 23.85 2316 3447 0.0141 0.0462
700 000 354.7 34 0.907 23.04 2161 3216 0.0151 0.0495
650 000 329.4 34 0.874 22.20 2007 2987 0.0163 0.0535
600 000 304.0 34 0.840 21.34 1883 2802 0.0177 0.0581
550 000 278.7 34 0.804 20.42 1698 2527 0.0192 0.0630
500 000 253.4 30 0.766 19.46 1544 2298 0.0212 0.0695
450 000 228.0 30 0.727 18.47 1389 2067 0.0235 0.0771
400 000 202.7 24 0.685 17.40 1235 1838 0.0264 0.0866
350 000 177.3 24 0.641 16.28 1081 16.09 0.3002 0.0991
300 000 152.0 18 0.594 15.09 926.3 1379 0.0353 0.1158
250 000 126.7 18 0.542 13.77 771.9 1149 0.0423 0.1387
211 600 0000 107.2 17 0.498 12.65 653.1 972.0 0.0500 0.1640
167 800 000 85.03 15 0.443 11.25 518.1 771.1 0.0630 0.2066
133 100 00 67.44 12 0.395 10.03 410.9 611.5 0.0795 0.2607
105 600 0 53.51 7 0.352 8.94 325.8 484.9 0.100 0.328
83 690 1 42.41 7 0.313 7.95 258.4 384.6 0.127 0.417
66 360 2 33.63 6 0.283 7.19 204.9 305.0 0.159 0.521
52 620 3 26.66 6 0.252 6.40 162.5 241.8 0.201 0.659
41 740 4 21.15 6 0.225 5.72 128.9 191.8 0.253 0.830
33 090 5 16.77 6 0.200 5.08 102.2 152.1 0.319 1.046
26 240 6 13.30 6 0.178 4.52 81.05 120.6 0.403 1.322
20 820 7 10.55 6 0.159 4.04 64.28 95.67 0.509 1.669
16 510 8 8.366 6 0.142 3.61 50.97 75.86 0.640 2.099
13 090 9 6.633 6 0.126 3.20 40.42 60.16 0.809 2.653
10 380 10 5.260 6 0.113 2.87 32.06 47.71 1.02 3.35
6 530 12 3.309 6 0.089 2.26 20.16 30.00 1.63 5.35
4 110 14 2.083 6 0.071 1.80 12.68 18.87 2.58 8.46
2 580 16 1.307 6 0.054 1.37 7.974 11.87 4.10 13.45
1 620 18 0.8209 6 0.043 1.09 5.015 7.464 6.54 21.45
1 020 20 0.5168 6 0.034 0.86 3.154 4.694 10.3 33.8
640 22 0.3243 6 0.027 0.69 1.992 2.965 16.4 53.8
404 24 0.2047 6 0.022 0.56 1.249 1.859 26.1 85.6
5.2 Before stranding, the copper wire used shall meet all of 5.3 In SIWcompressed conductors, the central core shall be
the requirements of the following specifications ofASTM that made of wire of the same type and temper as the concentric
are applicable to its type: layers, unless otherwise specified.
5.2.1 Specification B3,
6. Joints
5.2.2 Specification B33,
5.2.3 Specification B2, 6.1 Welds and brazes may be made in rods or in wires prior
5.2.4 Specification B1, to final drawing.Welds and brazes may be made in the finished
5.2.5 Specification B189, and individual wires composing the conductor, but shall not be
5.2.6 Specification B246. closer together than prescribed in Table 2.
B902/B902M−13 (2018)
TABLE 2 Minimum Distance Between Joints in Completed
addition to the 5 allowed in 9.4.1), but in no case shall the
Conductor
elongation of any individual wire be less than 5 %.
Number of Hard or Soft Temper
9.5 In the event that the requirements prescribed in 9.4.2 are
Wires in Medium-Hard
Conductor Temper
met but those prescribed in 9.4.1 are not met, a retest shall be
3to19 50ft 1ft permitted wherein all wires of the conductor shall be tested for
A
20 to 36 50 ft 1 ft in a layer
the purpose of final determination of conformance to 9.4.
A
37 to 60 25 ft 1 ft in a layer
A
61 and over 5 ft 1 ft in a layer
9.6 Elongation tests to determine compliance shall not be
A
Except as indicated, the limitations apply to closeness of joints throughout the
made on the conductor as a unit.
completed conductor.
9.7 If a tinning, lead-coating, or lead-alloy-coating test is
required, it shall be made on the wires prior to stranding.
10. Physical and Electrical Tests of Conductors Stranded
7. Lay
of Hard-Drawn or Medium-Hard-Drawn Wires
7.1 For stranded conductors, the lay length of a layer of
10.1 Tests for the physical and electrical properties of wires
wires shall be not less than 8 nor more than 16 times the outer
composing conductors made from hard-drawn or medium-
diameter of the finished conductor. For conductors of 37 wires
hard-drawnwires,uncoatedorcoated,shallbemadebeforebut
or more, this requirement shall apply to the wires in the outer
not after stranding.
two layers only.
10.2 At the option of the purchaser, tension and elongation
7.2 For stranded conductors, the direction of lay of the outer
tests on hard-drawn and medium-hard-drawn wires, uncoated
layer shall be left hand and may be reversed or unidirectional/
or coated, before stranding may be waived, and the completed
unilay in successive layers, unless otherwise specified by the
hard-drawn and medium-hard-drawn conductors may be tested
purchaser.
asaunit.Thebreakingstrengthofthebareconductorssotested
7.3 Other lays for special purposes shall be furnished by
shall be at least 90 % of the total of the specified minimum
special agreement between the manufacturer and the purchaser
breaking strengths of the component wires. The maximum
(Explanatory Note 5).
breaking strength of conductors made from medium-hard-
drawn wires, uncoated or coated, shall be not greater than the
8. Construction
sum of the specified maximum breaking strengths of the
8.1 The areas of cross section, minimum number of wires,
component wires. The minimum breaking strength of wires
and diameters of strands for SIW compressed stranded con- shall be calculated using specified nominal diameters and
ductors shal
...