ASTM B172-95

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
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Designation: B 172 – 95
Standard Specification for
Rope-Lay-Stranded Copper Conductors Having Bunch-
Stranded Members, for Electrical Conductors
This standard is issued under the fixed designation B 172; 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 conductors having bunch-stranded members are classifed as
follows:
1.1 This specification covers bare rope-lay-stranded con-
3.1.1 Class I—Conductors consisting of wires 0.0201 in.
ductors having bunch-stranded members made from round
(0.511 mm) diameter (No. 24 AWG) to produce rope-lay-
copper wires, either uncoated or coated with tin, lead, or
stranded conductors up to 2 000 000 cmil (1013 mm ) in total
lead-alloy for use as electrical conductors (Explanatory Notes
cross-sectional area. (Typical use is for special apparatus
1 and 2).
conductor.)
1.2 Coated wires shall include only those wires with fin-
3.1.2 Class K—Conductors consisting of wires 0.0100 in.
ished diameters and densities substantially equal to the respec-
(0.254 mm) diameter (No. 30 AWG) to produce rope-lay-
tive diameters and densities of uncoated wires.
stranded conductors up to 1 000 000 cmil (507 mm ) in total
1.3 The SI values for density are regarded as the standard.
cross-sectional area. (Typical use is for special portable cord
For all other properties the inch-pound values are to be
and conductors.)
regarded as standard and the SI units may be approximate.
3.1.3 Class M—Conductors consisting of wires 0.0063 in.
2. Referenced Documents
(0.160 mm) diameter (No. 34 AWG) to produce rope-lay-
stranded conductors up to 1 000 000 cmil (507 mm ) in total
2.1 The following documents of the issue in effect at the
cross-sectional area. (Typical use is for welding conductors.)
time of reference form a part of this specification to the extent
referenced herein:
4. Ordering Information
2.2 ASTM Standards:
2 4.1 Orders for material under this specification shall include
B 3 Specification for Soft or Annealed Copper Wire
the following information:
B 33 Specification for Tinned Soft or Annealed Copper
2 4.1.1 Quantity of each size and class,
Wire for Electrical Purposes
4.1.2 Conductor size: circular-mil area or AWG (see 7.1),
B 173 Specification for Rope-Lay-Stranded Copper Con-
4.1.3 Class (Section 4 and Table 1),
ductors Having Concentric-Stranded Members, for Elec-
4.1.4 Whether coated or uncoated; if coated, designate type
trical Conductors
of coating (see 11.1),
B 189 Specification for Lead-Coated and Lead-Alloy-
4.1.5 Details of special-purpose lays, if required (see 6.2
Coated Soft Copper Wire for Electrical Purposes
and 6.3 and Explanatory Note 3),
B 263 Test Method for Determination of Cross-Sectional
4.1.6 Package size (see 15.1),
Area of Stranded Conductors
4.1.7 Special package marking, if required (Section 14),
B 354 Terminology Relating to Uninsulated Metallic Elec-
4.1.8 Lagging, if required (see 15.2), and
trical Conductors
4.1.9 Place of inspection (Section 13).
2.3 American National Standard:
4.1.10 In addition, Supplementary Requirements shall apply
ANSI C42.35 Definitions of Electrical Terms
only when specified by the purchaser in the inquiry, contract, or
3. Classification
purchase order for direct procurement by agencies of the U.S.
Government (S1, S2, and S3).
3.1 For the purpose of this specification rope-lay-stranded
5. Joints
This specification is under the jurisdiction of ASTM Committee B-1 on
5.1 Necessary joints in wires or in groups of wires shall be
Electrical Conductors and is the direct responsibility of Subcommittee B01.04 on
made in accordance with accepted commercial practice, taking
Conductors of Copper and Copper Alloys.
into account the size of the wire or group of wires as related to
Current edition effective July 15, 1995. Published September 1995. Originally
issued 1942 to replace portions of B 158–41 T. Last previous edition B 172 – 90.
the size of the entire conductor.
Annual Book of ASTM Standards, Vol 02.03.
5.2 Bunch-stranded members or rope-stranded members
Available from American National Standards Institute, 11 West 42nd Street,
forming the completed conductor may be joined as a unit by
13th Floor, New York, NY 10036.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
B 172
A
TABLE 1 Construction Requirements of Rope-Lay Stranded Copper Conductors Having Bunch-Stranded Members
Class I Class K Class M
Wire Wire Wire
Area of
Diameter Diameter Diameter
Cross
0.0201 0.0100 0.0063
Section
Size in. in. in.
AWG (0.511 Approximate (0.254 Approximate (0.160 Approximate
B B B
mm) Mass mm) Mass mm) Mass
cmil mm Nominal Strand lb/ kg/ Nominal Strand lb/ kg/ Nominal Strand lb/ kg/
C C C
Number Construction 1000 ft. km Number Construction 1000 ft. km Number Construction 1000 ft. km
of Wires of Wires of Wires
2 000 000 1013 . 4921 19 by 7 by 37 6439 9583 . .
1 900 000 963 . 4788 19 by 7 by 36 6265 9324 . .
1 800 000 912 . 4522 19 by 7 by 34 5917 8806 . .
1 750 000 887 . 4389 19 by 7 by 33 5743 8547 . .
1 700 000 861 . 4256 19 by 7 by 32 5569 8288 . .
1 600 000 811 . 3990 19 by 7 by 30 5221 7770 . .
1 500 000 760 . 3724 19 by 7 by 28 4873 7252 . .
1 400 000 709 . 3458 19 by 7 by 26 4525 6734 . .
1 300 000 659 . 3192 19 by 7 by 24 4177 6216 . .
1 250 000 633 . 3059 19 by 7 by 23 4003 5957 . .
1 200 000 608 . 2926 19 by 7 by 22 3829 5698 . .
1 100 000 557 . 2793 19 by 7 by 21 3655 5439 . .
1 000 000 507 . 2527 19 by 7 by 19 3307 4921 10 101 37 by 7 by 39 3272 4869 25 193 61 by 7 by 59 3239 4819
900 000 456 . 2261 19 by 7 by 17 2959 4403 9065 37 by 7 by 35 2936 4369 22 631 61 by 7 by 53 2909 4329
800 000 405 . 1995 19 by 7 by 15 2611 3885 7980 19 by 7 by 60 2585 3846 20 069 61 by 7 by 47 2580 3839
750 000 380 . 1862 19 by 7 by 14 2436 3626 7581 19 by 7 by 57 2455 3654 18 788 61 by 7 by 44 2415 3594
700 000 355 . 1729 19 by 7 by 13 2262 3367 6916 19 by 7 by 52 2240 3333 17 507 61 by 7 by 41 2251 3349
650 000 329 . 1596 19 by 7 by 12 2088 3108 6517 19 by 7 by 49 2111 3141 16 226 61 by 7 by 38 2086 3104
600 000 304 . 1470 7 by 7 by 30 1906 2836 5985 19 by 7 by 45 1938 2885 14 945 61 by 7 by 35 1921 2859
550 000 279 . 1372 7 by 7 by 28 1779 2647 5453 19 by 7 by 41 1766 2628 13 664 61 by 7 by 32 1757 2614
500 000 253 . 1225 7 by 7 by 25 1588 2363 5054 19 by 7 by 38 1637 2436 12 691 37 by 7 by 49 1631 2428
450 000 228 . 1127 7 by 7 by 23 1461 2174 4522 19 by 7 by 34 1465 2180 11 396 37 by 7 by 44 1465 2180
400 000 203 . 980 7 by 7 by 20 1270 1891 3990 19 by 7 by 30 1292 1923 10 101 37 by 7 by 39 1298 1932
350 000 177 . 882 7 by 7 by 18 1143 1701 3458 19 by 7 by 26 1120 1667 8806 37 by 7 by 34 1132 1685
300 000 152 . 735 7 by 7 by 15 953 1418 2989 7 by 7 by 61 959 1427 7581 19 by 7 by 57 975 1450
250 000 127 . 637 7 by 7 by 13 826 1229 2499 7 by 7 by 51 802 1193 6384 19 by 7 by 48 821 1221
211 600 107 0000 532 19 by 28 683 1017 2107 7 by 7 by 43 676 1006 5320 19 by 7 by 40 684 1018
167 800 85.0 000 418 19 by 22 537 799 1666 7 by 7 by 34 535 795 4256 19 by 7 by 32 547 814
133 100 67.4 00 342 19 by 18 439 654 1323 7 by 7 by 27 424 632 3325 19 by 7 by 25 427 636
105 600 53.5 0 266 19 by 14 342 508 1064 19 by 56 338 503 2646 7 by 7 by 54 337 501
83 690 42.4 1 210 7 by 30 267 397 836 19 by 44 266 395 2107 7 by 7 by 43 268 399
66 360 33.6 2 161 7 by 23 205 305 665 19 by 35 211 315 1666 7 by 7 by 34 212 316
52 620 26.7 3 133 7 by 19 169 252 532 19 by 28 169 252 1323 7 by 7 by 27 168 251
41 740 21.1 4 105 7 by 15 134 199 420 7 by 60 132 197 1064 19 by 56 134 200
33 090 16.8 5 84 7 by 12 107 159 336 7 by 48 106 157 836 19 by 44 105 157
26 240 13.3 6 63 7 by 9 80 119 266 7 by 38 84 125 665 19 by 35 84 125
20 820 10.5 7 . 210 7 by 30 66 98 532 19 by 28 67 100
16 510 8.37 8 . 168 7 by 24 53 79 420 7 by 60 52 78
13 090 6.63 9 . 133 7 by 19 42 62 336 7 by 48 42 62
10 380 5.26 10 . . 259 7 by 37 32 48
6530 3.31 12 . . 168 7 by 24 21 31
A
The constructions shown in this table are typical of those used in the industry. It is not intended that this table preclude other constructions using the same total number
of wires which may be desireable for specific applications. The constructions shown provide for a finished, non-covered, stranded conductor approximately of the area
indicated. When specified by the purchaser, the number or size of wires may be increased to provide additional area to compensate for draw-down during subsequent
processing.
B
Values for the mass of the completed conductor are approximate. The mass values are based upon the standard stranding increments listed in Explanatory Note 6.
C
Strand Construction—#A by #B by #C: where #C is the number of wires in each bunch-stranded member; #B is the number of bunch stranded members which
make-up each rope-stranded member; and #A (where used) is the number of rope-stranded members in the conductor. Where #A is not given, the conductor consists of
one rope-stranded member. For example, 19 by 7 by 32 indicates a construction consisting of 19 rope-stranded members, each of which consists of 7 bunch-stranded
members with 32 wires each.
soldering, brazing, or welding. 6.2 The length of lay of the outer layer of the rope-lay-
5.3 Joints shall be so constructed and so disposed through- stranded conductor shall not be less than 8 nor more than 16
out the conductor that the diameter or configuration of the
times the outside diameter of the completed conductor. The
completed conductor is not substantially affected, and so that
length of lay of the other layers shall be at the option of the
the flexibility of the completed conductor is not adversely
manufacturer unless specifically agreed upon. The direction of
affected.
lay of the outer layer shall be left-hand, unless the direction of
lay is specified otherwise by the purchaser. The direction of lay
6. Lay (Explanatory Note 3)
of the other layers shall be reversed in successive layers, unless
6.1 Conductors of the same size and description furnished
otherwise agreed upon by the manufacturer and the purchaser.
on one order shall have the same lay.
B 172
6.3 The length of lay of the bunch-stranded and rope- 8.7 If a tinning, lead-coating, or lead alloy-coating test is
stranded members shall be not more than 30 times the outside required, it shall be made on the wires prior to stranding.
diameter of the member. The direction of lay shall be at the
9. Density
opt
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