ASTM B174-17

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Designation: B174 − 10 (Reapproved 2015) B174 − 17
Standard Specification for
Bunch-Stranded Copper Conductors for Electrical
Conductors
This standard is issued under the fixed designation B174; 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 bunch-stranded conductors made from round copper wires, either uncoated or coated with tin,
lead, or lead-alloy for use as electrical conductors (Explanatory Note 1 and Explanatory Note 2).
1.2 Coated wires shall include only those wires with finished diameters and densities substantially equal to the respective
diameters and densities of uncoated wires.
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.
1.3.1 For conductor sizes designated by AWG or kcmil, 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.
1.4 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 at the time of reference form a part of this specification to the extent
referenced herein:
2.2 ASTM Standards:
B3 Specification for Soft or Annealed Copper Wire
B33 Specification for Tin-Coated Soft or Annealed Copper Wire for Electrical Purposes
B172 Specification for Rope-Lay-Stranded Copper Conductors Having Bunch-Stranded Members, for Electrical Conductors
B189 Specification for Lead-Coated and Lead-Alloy-Coated Soft Copper Wire for Electrical Purposes
B193 Test Method for Resistivity of Electrical Conductor Materials
B263 Test Method for Determination of Cross-Sectional Area of Stranded Conductors
B354 Terminology Relating to Uninsulated Metallic Electrical Conductors
2.3 American National Standard:
ANSI C42.35 Definitions of Electrical Terms
3. Classification
3.1 For the purpose of this specification bunch-stranded conductors are classified as shown in Tables 1 and 2.
This specification is under the jurisdiction of ASTM Committee B01 on Electrical Conductors and is the direct responsibility of Subcommittee B01.04 on Conductors
of Copper and Copper Alloys.
Current edition approved April 1, 2015April 1, 2017. Published April 2015April 2017. Originally approved in 1941. Last previous edition approved in 20102015 as B174 –
10. 10 (2015). DOI: 10.1520/B0174-10R15.10.1520/B0174-17.
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.
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B174 − 17
A
TABLE 1 A Classification and Construction Requirements of Bunch-Stranded Conductors —Class I Bunch Stranded Conductors
Area of Classification, Uncoated Copper Coated Copper
Cross Section Size,
and
Minimum
Number
of Wires
Size, Class I Nominal dc Maximum dc Nominal dc Maximum dc Nominal dc Maximum dc Nominal dc Maximum dc
AWG Nominal resistance resistance resistance resistance resistance resistance resistance resistance
Wire @20C @20C @20C @20C @20C @20C @20C @20C
Diameter
0.0201 In.
(0.511 mm)
cmil mm 24 AWG ohm/kft ohm/kft ohm/km ohm/km ohm/kft ohm/kft ohm/km ohm/km
20820 10.5 7 52 0.508 0.518 1.67 1.70 0.528 0.539 1.73 1.77
16510 8.37 8 41 0.641 0.654 2.10 2.14 0.666 0.679 2.19 2.23
13090 6.63 9 33 0.808 0.824 2.65 2.70 0.840 0.857 2.76 2.81
10380 5.26 10 26 1.02 1.04 3.34 3.41 1.06 1.08 3.48 3.55
A
TABLE 1 B Classification and Construction Requirements of Bunch-Stranded Conductors—Class J Bunch Stranded Conductors
Area of Classification, Uncoated Copper Coated Copper
Cross Section Size,
and
Minimum
Number
of Wires
Size, Class J Nominal Maximum Nominal Maximum Nominal Maximum Nominal Maximum
AWG Nominal dc dc dc dc dc dc dc dc
Wire resistance resistance resistance resistance resistance resistance resistance resistance
Diameter @20C @20C @20C @20C @20C @20C @20C @20C
0.0126 In.
(0.320 mm)
cmil mm 28 AWG ohm/kft ohm/kft ohm/km ohm/km ohm/kft ohm/kft ohm/km ohm/km
10380 5.26 10 65 1.02 1.04 3.34 3.41 1.08 1.10 3.54 3.61
6530 3.31 12 41 1.62 1.65 5.31 5.42 1.72 1.75 5.64 5.76
4110 2.08 14 26 2.57 2.62 8.44 8.61 2.73 2.79 8.96 9.14
2580 1.31 16 16 4.10 4.18 13.5 13.7 4.35 4.44 14.3 14.6
1620 0.821 18 10 6.53 6.66 21.4 21.9 6.94 7.07 22.8 23.2
1020 0.517 20 7 10.4 10.6 34.0 34.7 11.0 11.2 36.1 36.8
A
TABLE 1 C Classification and Construction Requirements of Bunch-Stranded Conductors—Class K Bunch Stranded Conductors
Area of Classification, Uncoated Copper Coated Copper
Cross Section Size,
and
Minimum
Number
of Wires
Area of Classification, Uncoated Copper Coated Copper
Cross Section Size,
and
inimum
Number
of Wires
Size, Class K Nominal Maximum Nominal Maximum Nominal Maximum Nominal Maximum
AWG Nominal dc dc dc dc dc dc dc dc
Wire resistance resistance resistance resistance resistance resistance resistance resistance
Diameter @20C @20C @20C @20C @20C @20C @20C @20C
0.0100 In.
(0.254 mm)
cmil mm 30 AWG ohm/kft ohm/kft ohm/km ohm/km ohm/kft ohm/kft ohm/km ohm/km
10380 5.26 10 104 1.02 1.04 3.35 3.41 1.09 1.12 3.58 3.65
6530 3.31 12 65 1.62 1.65 5.31 5.42 1.74 1.77 5.71 5.82
4110 2.08 14 41 2.57 2.62 8.43 8.60 2.76 2.82 9.06 9.24
2580 1.31 16 26 4.10 4.18 13.5 13.7 4.40 4.49 14.4 14.7
1620 0.821 18 16 6.53 6.66 21.4 21.9 7.01 7.15 23.0 23.5
B
1020 0.517 20 10 10.4 10.6 34.1 34.8 11.1 11.4 36.4 37.1
640 0.324 22 7 16.5 16.9 54.1 55.2 17.7 18.1 58.1 59.2
A
The constructions shown in these tables are typical of those used in the industry. It is intended that these tables preclude other constructions which may be desirable
for specific applications. The constructions shown provide for a finished stranded conductor approximately of the area indicated. When specified by the purchaser, the
number or sizes of wire may be increased to provide additional area to compensate for draw-down during subsequent processing.
B
As an alternate to the construction shown for 20 AWG, Class K; for hook-up wire construction may consist of 8 wires 0.0100 in. (0.254 mm) diameter around wire of 0.0142
in. (0.361 mm) diameter.
B174 − 17
TABLE 2 Classification and Construction Requirements of Bunch-Stranded Conductors—Class L, M, O, P and Q Bunch Stranded
A
Conductors
Area of Classification, Uncoated Copper Coated Copper
Cross Section Size, and
Minimum Number
of Wires
Size, Class L Class M Class O Class P Class Q Nominal Maximum Nominal Maximum Nominal Maximum Nominal Maximum
AWG dc dc dc dc dc dc dc dc
resistanceresistanceresistanceresistance resistance resistanceresistanceresistance
@20C @20C @20C @20C @20C @20C @20C @20C
Nominal Nominal Nominal Nominal Nominal
Wire Wire Wire Wire Wire
Diameter Diameter Diameter Diameter Diameter
0.0080 In. 0.0063 In. 0.0050 In. 0.0040 In. 0.0031 In.
(0.511 (0.320 (0.254 (0.320 (0.254
mm) mm) mm) mm) mm)
cmil mm 32 AWG 34 AWG 36 AWG 38 AWG 40 AWG ohm/kft ohm/kft ohm/km ohm/km ohm/kft ohm/kft ohm/km ohm/km
10380 5.26 10 165 . . . . 1.02 1.04 3.34 3.41 1.09 1.12 3.58 3.65
6530 3.31 12 104 . . . . 1.62 1.65 5.31 5.42 1.74 1.77 5.71 5.82
4110 2.08 14 65 104 . . . 2.57 2.62 8.43 8.60 2.76 2.82 9.06 9.24
2580 1.31 16 41 65 104 165 . 4.10 4.18 13.5 13.7 4.40 4.49 14.4 14.7
1620 0.821 18 26 41 65 104 165 6.53 6.66 21.4 21.9 7.00 7.15 23.0 23.4
1020 0.517 20 16 26 41 65 104 10.4 10.6 34.1 34.8 11.1 11.4 36.4 37.1
640 0.324 22 . 19 . . . 16.5 16.9 54.1 55.2 17.7 18.1 58.1 59.2
404 0.205 24 7 . 19 . . 26.2 26.7 86.0 87.7 28.1 28.7 92.2 94.0
253 0.128 26 . 7 . . . 41.8 42.6 137 140 44.9 45.8 147 150
A
The constructions shown in this table are typical of those used in the industry. It is intended that this table preclude other constructions which may be desirable for specific
applications. The constructions shown provide for a finished stranded conductor approximately of the area indicated. When specified by the purchaser, the number or sizes
of wire may be increased to provide additional area to compensate for draw-down during subsequent processing.
4. Ordering Information
4.1 Orders for material under this specification shall include the following information:
4.1.1 Quantity of each size and class,
4.1.2 Conductor size: circular-mil area or AWG (see 7.1),
4.1.3 Class (Section 3 and Table 3),
4.1.4 Whether coated or uncoated; if coated, designate type of coating (see 11.1),
4.1.5 Maximum length of lay (see 6.3),
4.1.6 Whether separator is required (see 7.2),
4.1.7 Package size (see section 14.1),
4.1.8 Special package marking, if required (Section 14), and
4.1.9 Place of inspection (Section 13).
5. Joints
5.1 Necessary joints in wires shall be made in accordance with accepted commercial practice.
TABLE 3 Maximum Length of Lay for Bunch-Stranded
Conductors
Maximum Length of Lay
Area of
Size, Nominal Column Column
Cross Section
AWG Diameter A B
cmil mm in. mm in. mm in. mm
20 820 10.5 7 0.167 4.24 3.00 76.20 3.00 76.20
16 510 8.37 8 0.149 3.78 2.75 69.85 2.75 69.85
13 090 6.63 9 0.133 3.38 2.50 63.50 2.50 63.50
10 380 5.26 10 0.118 3.00 2.50 63.50 2.50 63.50
6 530 3.31 12 0.093 2.36 2.00 50.80 2.00 50.80
4 110 2.08 14 0.074 1.88 2.00 50.80 1.75 44.45
2 580 1.31 16 0.059 1.50 2.00 50.80 1.50 38.10
1 620 0.821 18 0.047 1.19 2.00 50.80 1.25 31.75
1 020 0.517 20 0.037 0.94 2.00 50.80 1.00 25.40
640 0.324 22 0.030 0.76 1.30 33.02 0.80 20.32
404 0.205 24 0.024 0.61 1.20 30.48 0.70 17.78
253 0.128 26 0.019 0.48 1.00 25.40 0.60 15.24
159 0.0806 28 0.015 0.38 1.00 25.40 0.5
...