ASTM B8-99

Standard Specification for Concentric-Lay-Stranded Copper Conductors, Hard, Medium-Hard, or Soft

SCOPE
1.1 This specification covers bare concentric-lay-stranded conductors made from round copper wires, either uncoated or coated with tin, lead, or lead alloy for general use for electrical purposes. These conductors shall be constructed with a central core surrounded by one or more layers of helically laid wires. Note 1-This specification also permits conductors for use as covered or insulated electrical conductors. Note 2-Sealed conductors, that are intended to prevent longitudinal water propagation and are further covered/insulated, are also permitted within the guidelines of this specification.
1.2 For the purposes of this specification, conductors are classified as follows (Explanatory Notes 1 and 2):
1.2.1 Class AA -For bare conductors usually used in overhead lines.
1.2.2 Class A -For conductors to be covered with weather-resistant (weather-proof), slow-burning, materials, and for bare conductors where greater flexibility than is afforded by Class AA is required.
1.2.3 Class B -For conductors to be insulated with various materials such as rubber, paper, varnished cloth, etc., and for the conductors indicated under Class A where greater flexibility is required.
1.2.4 Class C and Class D -For conductors where greater flexibility is required than is provided by Class B conductors.
1.3 The SI values for density are regarded as the standard. For all other properties, the inch-pound values are to be regarded as standard and the SI units may be approximate.

General Information

• Status: Historical
• Publication Date: 09-Apr-1999
• ICS: 29.060.20 - Cables
• Technical Committee: B01 - Electrical Conductors
• Drafting Committee: B01.04 - Conductors of Copper and Copper Alloys

Relations

• Replaced By: ASTM B8-04 - Standard Specification for Concentric-Lay-Stranded Copper Conductors, Hard, Medium-Hard, or Soft
• Effective Date: 01-Apr-2004
• Referred By: ASTM F1835-97(2018) - Standard Guide for Cable Splicing Installations
• Effective Date: 10-Apr-1999
• Referred By: ASTM F1883-20 - Standard Practice for Selection of Wire and Cable Size in AWG or Metric Units
• Effective Date: 10-Apr-1999
• Referred By: ASTM B784-01(2017)e1 - Standard Specification for Modified Concentric-Lay-Stranded Copper Conductors for Use in Insulated Electrical Cables
• Effective Date: 10-Apr-1999
• Referred By: ASTM B226-11(2021) - Standard Specification for Cored, Annular, Concentric-Lay-Stranded Copper Conductors
• Effective Date: 10-Apr-1999
• Referred By: ASTM B173-17 - Standard Specification for Rope-Lay-Stranded Copper Conductors Having Concentric-Stranded Members, for Electrical Conductors
• Effective Date: 10-Apr-1999
• Referred By: ASTM B913-21 - Standard Test Method for Evaluation of Crimped Electrical Connections to 16-Gauge and Smaller Diameter Stranded and Solid Conductors
• Effective Date: 10-Apr-1999

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: B 8 – 99
Standard Specification for
Concentric-Lay-Stranded Copper Conductors, Hard,
Medium-Hard, or Soft
This standard is issued under the fixed designation B 8; 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 (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope B 3 Specification for Soft or Annealed Copper Wire
B 33 Specification for Tinned Soft or Annealed Copper
1.1 This specification covers bare concentric-lay-stranded
Wire for Electrical Purposes
conductors made from round copper wires, either uncoated or
B 172 Specification for Rope-Lay-Stranded Copper Con-
coated with tin, lead, or lead alloy for general use for electrical
ductors Having Bunch-Stranded Members, for Electrical
purposes. These conductors shall be constructed with a central
Conductors
core surrounded by one or more layers of helically laid wires.
B 173 Specification for Rope-Lay-Stranded Copper Con-
NOTE 1—This specification also permits conductors for use as covered
ductors Having Concentric-Stranded Members, for Elec-
or insulated electrical conductors.
trical Conductors
NOTE 2—Sealed conductors, that are intended to prevent longitudinal
B 174 Specification for Bunch-Stranded Copper Conduc-
water propagation and are further covered/insulated, are also permitted
tors for Electrical Conductors
within the guidelines of this specification.
B 189 Specification for Lead-Coated and Lead-Alloy-
1.2 For the purposes of this specification, conductors are
Coated Soft Copper Wire for Electrical Purposes
classified as follows (Explanatory Note 1 and Note 2):
B 193 Test Method for Resistivity of Electrical Conductor
1.2.1 Class AA—For bare conductors usually used in over-
Materials
head lines.
B 246 Specification for Tinned Hard-Drawn and Medium-
1.2.2 Class A—For conductors to be covered with weather-
Hard-Drawn Copper Wire for Electrical Purposes
resistant (weather-proof), slow-burning, materials, and for bare
B 263 Test Method for Determination of Cross-Sectional
conductors where greater flexibility than is afforded by Class
Area of Stranded Conductors
AA is required.
B 354 Terminology Relating to Uninsulated Metallic Elec-
1.2.3 Class B—For conductors to be insulated with various
trical Conductors
materials such as rubber, paper, varnished cloth, etc., and for
B 787 Specification for 19 Wire Combination Unilay-
the conductors indicated under Class A where greater flexibility
Stranded Copper Conductors for Subsequent Insulation
is required.
1.2.4 Class C and Class D—For conductors where greater
3. Ordering Information
flexibility is required than is provided by Class B conductors.
3.1 Orders for material under this specification shall include
1.3 The SI values for density are regarded as the standard.
the following information:
For all other properties, the inch-pound values are to be
3.1.1 Quantity of each size and class,
regarded as standard and the SI units may be approximate.
3.1.2 Conductor size: circular-mil area or AWG (Section 6),
3.1.3 Class (see 1.2 and Table 1),
2. Referenced Documents
3.1.4 Temper (see 13.2),
2.1 ASTM Standards:
3.1.5 Whether coated or uncoated; if coated, designate type
B 1 Specification of Hard-Drawn Copper Wire
of coating (see 13.1 and 13.2),
B 2 Specification for Medium-Hard-Drawn Copper Wire
3.1.6 Details of special-purpose lays, if required (see 5.4),
3.1.7 When physical tests shall be made (see 8.2 and 8.3),
3.1.8 Package size (see 8.1),
This specification is under the jurisdiction of ASTM Committee B-1 on
Electrical Conductors and is the direct responsibility of Subcommittee B01.04 on
3.1.9 Lagging, if required (see section 15.2),
Conductors of Copper and Copper Alloys.
3.1.10 Special package marking, if required (Section 14),
Current edition approved April 10, 1999. Published June 1999. Originally
and
published as B8 – 15 T. Last previous edition B8 – 95.
3.1.11 Place of inspection (Section 15).
Annual Book of ASTM Standards, Vol 02.03.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
B 8–99
TABLE 1 Construction Requirements of Concentric-Lay-Stranded Copper Conductors
A
Area of Size,
Class AA Class A Class B Class C Class D
Cross-Section American (or
Number of Diameter of Number of Diameter of Number of Diameter of Number of Diameter of Number of Diameter of
cmil B & S) Wire
Wires Wires, mils Wires Wires, mils Wires Wires, mils Wires Wires, mils Wires Wires, mils
Gage
*5 000 000 . . . 169 172.0 217 151.8 271 135.8 271 135.8
4 500 000 . . . 169 163.2 217 144.0 271 128.9 271 128.9
4 000 000 . . . 169 153.8 217 135.8 271 121.5 271 121.5
3 500 000 . . . 127 166.0 169 143.9 217 127.0 271 113.6
*3 000 000 . . . 127 153.7 169 133.2 217 117.6 271 105.2
*2 500 000 . . . 91 165.7 127 140.3 169 121.6 217 107.3
*2 000 000 . . . 91 148.2 127 125.5 169 108.8 217 96.0
1 900 000 . . . 91 144.5 127 122.3 169 106.0 217 93.6
1 800 000 . . . 91 140.6 127 119.1 169 103.2 217 91.1
*1 750 000 . . . 91 138.7 127 117.4 169 101.8 217 89.8
1 700 000 . . . 91 136.7 127 115.7 169 100.3 217 88.5
1 600 000 . . . 91 132.6 127 112.2 169 97.3 217 85.9
*1 500 000 . . . 61 156.8 91 128.4 127 108.7 169 94.2
1 400 000 . . . 61 151.5 91 124.0 127 105.0 169 91.0
1 300 000 . . . 61 146.0 91 119.5 127 101.2 169 87.7
*1 250 000 . . . 61 143.1 91 117.2 127 99.2 169 86.0
1 200 000 . . . 61 140.3 91 114.8 127 97.2 169 84.3
1 100 000 . . . 61 134.3 91 109.9 127 93.1 169 80.7
*1 000 000 . 37 164.4 61 128.0 61 128.0 91 104.8 127 88.7
900 000 . 37 156.0 61 121.5 61 121.5 91 99.4 127 84.2
*800 000 . 37 147.0 61 114.5 61 114.5 91 93.8 127 79.4
*750 000 . 37 142.4 61 110.9 61 110.9 91 90.8 127 76.8
*700 000 . 37 137.5 61 107.1 61 107.1 91 87.7 127 74.2
650 000 . 37 132.5 61 103.2 61 103.2 91 84.5 127 71.5
*600 000 . 37 127.3 37 127.3 61 99.2 91 81.2 127 68.7
550 000 . 37 121.9 37 121.9 61 95.0 91 77.7 127 65.8
*500 000 . 19 162.2 37 116.2 37 116.2 61 90.5 91 74.1
450 000 . 19 153.9 37 110.3 37 110.3 61 85.9 91 70.3
*400 000 . 19 145.1 19 145.1 37 104.0 61 81.0 91 66.3
*350 000 . 12 170.8 19 135.7 37 97.3 61 75.7 91 62.0
*300 000 . 12 158.1 19 125.7 37 90.0 61 70.1 91 57.4
*250 000 . 12 144.3 19 114.7 37 82.2 61 64.0 91 52.4
*211 600 0000 7 173.9 7 173.9 19 105.5 37 75.6 61 58.9
*167 800 000 7 154.8 7 154.8 19 94.0 37 67.3 61 52.4
*133 100 00 7 137.9 7 137.9 19 83.7 37 60.0 61 46.7
*105 600 0 7 122.8 7 122.8 19 74.5 37 53.4 61 41.6
B
167.0 7 109.3 19 66.4 37 47.6 61 37.0
*83 690 1 3
B
*66 360 2 3 148.7 7 97.4 7 97.4 19 59.1 37 42.4
B
*52 620 3 3 132.5 7 86.7 7 86.7 19 52.6 37 37.7
B
*41 740 4 3 118.0 7 77.2 7 77.2 19 46.9 37 33.6
*33 090 5 . . . . 7 68.8 19 41.7 37 29.9
*26 240 6 . . . . 7 61.2 19 37.2 37 26.6
*20 820 7 . . . . 7 54.5 19 33.1 37 23.7
*16 510 8 . . . . 7 48.6 19 29.5 37 21.1
*13 090 9 . . . . 7 43.2 19 26.2 37 18.8
*10 380 10 . . . . 7 38.5 19 23.4 37 16.7
*6 530 12 . . . . 7 30.5 19 18.5 37 13.3
*4 110 14 . . . . 7 24.2 19 14.7 37 10.5
*2 580 16 . . . . 7 19.2 19 11.7 . .
*1 620 18 . . . . 7 15.2 19 9.2 . .
*1 020 20 . . . . 7 12.1 19 7.3 . .
*640 22 . . . . 7 9.6 19 5.8 . .
*404 24 . . . . 7 7.6 19 4.6 . .
* The sizes of conductors that have been marked with an asterisk provide for one or more schedules of preferred series, and are commonly used in the industry. The
sizes not marked are given simply as a matter of reference and it is suggested that their use be discouraged.
A
For unidirectional/unilay constructions the number of wires shown are minimum requirements.
B
Although Class AA conductors having three strands do not conform to the construction requirements of 1.1, they are listed in this table for convenience.
3.2 In addition, Supplementary Requirements shall apply composing hard-drawn or medium-harddrawn Class AA con-
only when specified by the purchaser in the inquiry, contract, or
ductors of seven wires or less. In other conductors, welds and
purchase order for direct procurement by agencies of the U. S.
brazes may be made in the finished individual wires composing
Government (S1, S2, and S3).
the conductor, but shall not be closer together than prescribed
in Table 2.
4. Joints
4.1 Welds and brazes may be made in rods or in wires prior
to final drawing. Joints may not be made in the finished wires
B 8–99
TABLE 2 Minimum Distance Between Joints in the Completed Conductor
Hard or Medium-Hard Soft
Number of Wires in
Conductor
Class AA Class A Class B Class C Class D All Classes
3 none permitted . . . . 1 ft
7 none permitted 50 ft 50 ft . . 1 ft
12 50 ft 50 ft . . . 1 ft
19 50 ft 50 ft 50 ft 50 ft . 1 ft
A
20 to 36 50 ft 50 ft 50 ft 50 ft . 1 ft in a layer
A
37 to 60 25 ft 25 ft 25 ft 25 ft 1 ft in a layer
A
61 and over . 5 ft 5 ft 5 ft 5 ft 1 ft in a layer
A
Except as indicated, the limitations apply to closeness of joints throughout the completed conductor.
5. Lay stranded conductor consisting of 7 wires or more may be
slightly compressed, thereby reducing the outside diameter of
5.1 For Class AA conductors composed of less than seven
the conductor to the nominal values shown in Table 3, provided
wires, the preferred lay is 11 times the outside diameter of the
that the area of cross section after stranding is in accordance
completed conductor, but shall be not less than 8 nor more than
with Section 11.
14 times this diameter.
5.2 For Class AA conductors composed of seven wires or
7. Physical and Electrical Tests of Conductors Stranded
more the preferred lay of a layer of wires is 13.5 times the
of Soft Wires
outside diameter of that layer, but shall be not less than 10 nor
7.1 Tests for the electrical properties of wires composing
more than 16 times this diameter.
conductors made from soft or annealed copper wire, bare or
5.3 For all other classes the lay of a layer of wires shall be
coated, shall be made before stranding.
not less than 8 nor more than 16 times the outside diameter of
7.2 Tests for the physical properties of soft or annealed
that layer, except that for conductors composed of 37 wires or
copper wire, bare or coated, may be made upon the wires
more, this requirement shall apply only to the two outer layers.
before stranding or upon wires removed from the complete
The lay of the layers other than the two outer layers shall be at
stranded conductor, but need not be made upon both. Care shall
the option of the manufacturer, unless otherwise agreed upon.
be taken to avoid mechanical injury to wire removed from the
5.3.1 For conductors to be used in covered or insulated
conductor for the purpose of testing.
wires or cables, the lay length shall be not less than 8 nor more
7.3 The physical properties of wire when tested before
than 16 times the outer diameter of the finished conductor. For
stranding shall conform to the applicable requirements of 13.2.
conductors of 37 wires or more, this requirement shall apply to
7.4 The physical properties of wires removed from the
the wires in the outer two layers. The lay of the layers other
completed stranded conductor shall be permitted to vary from
than the two outer layers shall be at the option of the
the applicable requirements of 13.2 by the following amounts
manufacturer, unless otherwise agreed upon.
5.4 Other lays for special purposes shall be furnished by (Explanatory Note 2):
7.4.1 Average of Results Obtained on All Wires Tested—The
special agreement between the manufacturer and the purchaser
(Explanatory Note 1). minimum elongation required shall be reduced in numerical
value 5 (for example, from 30 to 25 %) from the numerical
5.5 The direction of lay of the outer layer shall be left-hand,
requirements for the wire before stranding.
and for conductors having a nominal cross-sectional area larger
7.4.2 Results Obtained on Individual Wires—The elonga-
than No. 8 AWG, shall be reversed in successive layers, unless
tion of individual wires shall be reduced in numerical value 15
otherwise specified by the purchaser.
from the minimum requirements before stranding (that is, 10 in
5.5.1 For conductors to be used in covered or insulated
addition to the 5 allowed in 7.4.1), but in no case shall the
wires or cables, the direction of lay of the outer layer shall be
elongation of any individual wire be less than 5 %.
left hand and may be reversed or unidirectional/unilay in
7.5 In the event that the requirements prescribed in 7.4.2 are
successive layers, unless otherwise agreed upon.
met but those prescribed in 7.4.1 are not met, a retest shall be
6. Construction
permitted wherein all wires of the conductor shall be tested for
the purpose of final determination of conformance to 7.4.
6.1 The areas of cross section, numbers, and diameters of
7.6 Elongation tests to determine compliance shall not be
wires in the various classes of concentric-lay-stranded conduc-
made on the conductor as a unit.
tors shall conform to the requirements prescribed in Table 1
7.7 If a tinning, lead-coating, or lead-alloy-coating test is
(Explanatory Note 2).
required, it shall be made on the wires prior to stranding.
6.2 The diameters of the wires listed in Table 1 are nominal.
Where “combination strand” is required in order to insulate the
8. Physical and Electrical Tests of Conductors Stranded
conductor properly (strands in the outer layer having a larger
of Hard-Drawn or Medium-Hard-Drawn Wires
diameter than those in the inner layers) the diameters shall be
subject to a tolerance of 65 %, provided that the area of cross 8.1 Tests for the physical and electrical properties of wires
section after stranding is in accordance with Section 11. composing conductors made from hard-drawn or medium-
6.3 Where compressed stranding is required in order to hard-drawn wires, uncoated or coated, shall be made before but
insulate the conductor properly, one or more layers of any not after stranding.
B 8–99
TABLE 3 Diameters, Areas, and Mass of Concentric-Lay-Stranded Copper Conductors (Explanatory Note 8)
A
Nominal Conductor Diameter, in.
DC Resistance at
Mass
B
20°C
Concentric Strand
Reverse
Unilay
Size of Conductor, cmil or AWG numbers Concentric Area, in.
Com-
Compressed
C
Class AA Class A Class B pressed lbs/1000 ft kg/km V/1000 ft V/k
...