ASTM B971-10(2014)
(Specification)Standard Specification for Silver-Coated Braid and Ribbon Flat Copper Wire intended for use in Electronic Application
Standard Specification for Silver-Coated Braid and Ribbon Flat Copper Wire intended for use in Electronic Application
ABSTRACT
This specification covers silver-coated copper braid and ribbon flat wire intended for electronic application. Two classes of silver-coated braid and ribbon flat copper wire are covered: Class A (annealed temper) and Class H (hard-drawn). The material shall be silver-coated flat wire of such quality and purity that the finished product shall meet the properties and characteristics prescribed in this specification. The specification covers tensile properties, electrical resistivity requirements, permissible variations in thickness, and permissible variations in width.
SCOPE
1.1 This specification covers silver-coated copper braid and ribbon flat wire intended for electronic application (Explanatory Note 1).
1.2 Two classes of silver-coated braid and ribbon flat copper wire are covered as follows:
1.2.1 Class A—Annealed temper.
1.2.2 Class H—Hard-drawn.
1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
1.3.1 Exceptions—The SI values for density, resistivity, and volume are to be regarded as standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Designation:B971 −10 (Reapproved 2014)
Standard Specification for
Silver-Coated Braid and Ribbon Flat Copper Wire intended
for use in Electronic Application
This standard is issued under the fixed designation B971; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2.2 Other Standards:
NBS Handbook 100Copper Wire Tables
1.1 This specification covers silver-coated copper braid and
ribbon flat wire intended for electronic application (Explana-
3. Ordering Information
tory Note 1).
3.1 Ordersformaterialunderthisspecificationshallinclude
1.2 Twoclassesofsilver-coatedbraidandribbonflatcopper
the following information:
wire are covered as follows:
3.1.1 Quantity of each size,
1.2.1 Class A—Annealed temper.
3.1.2 Wire size-thickness and width in inches (see 5.4),
1.2.2 Class H—Hard-drawn.
3.1.3 Class of wire (see 1.2),
3.1.4 Type of copper, if special (see 4.2),
1.3 Thevaluesstatedininch-poundunitsaretoberegarded
3.1.5 Package size (see 10.1),
as standard. The values given in parentheses are mathematical
3.1.6 Special packaging marking, if required, and
conversions to SI units that are provided for information only
3.1.7 Place of inspection (see 7.1).
and are not considered standard.
1.3.1 Exceptions—The SI values for density, resistivity, and
4. Material
volume are to be regarded as standard.
4.1 The material shall be silver-coated flat wire (Explana-
1.4 This standard does not purport to address all of the
toryNote1)ofsuchqualityandpuritythatthefinishedproduct
safety concerns, if any, associated with its use. It is the
shall meet the properties and characteristics prescribed in this
responsibility of the user of this standard to establish appro-
specification.
priate safety and health practices and determine the applica-
4.2 Copper-Base Metal—The base metal shall be copper of
bility of regulatory limitations prior to use.
such quality and purity that the finished product shall have
properties and characteristics prescribed in this specification.
2. Referenced Documents
NOTE 1—Specifications B1, B3,or B49 define copper suitable for use.
2.1 ASTM Standards:
5. General Requirements (See Section 8)
B1Specification for Hard-Drawn Copper Wire
B3Specification for Soft or Annealed Copper Wire
5.1 Temper—The silver-coated flat wire conductor shall be
B49Specification for Copper Rod Drawing Stock for Elec-
provided in either hard-drawn condition (Class H) or annealed
trical Purposes
condition (Class A) as agreed upon between the manufacturer
B193Test Method for Resistivity of Electrical Conductor
and purchaser.
Materials
5.2 Tensile and Elongation (Explanatory Note 2):
B258 Specification for Nominal Diameters and Cross-
5.2.1 Class A—The silver-coated copper flat wire in the
SectionalAreasofAWGSizesofSolidRoundWiresUsed
annealed condition shall conform to the elongation require-
as Electrical Conductors
ments prescribed in Table 1. See Explanatory Note 3 for
equivalent round diameter calculations based on given thick-
nessandwidthdimensionsfortheflatwire.Forflatwirewhose
This test method is under the jurisdiction of ASTM Committee B01 on
nominal equivalent round diameter is more than 0.001 in.
Electrical Conductors and is the direct responsibility of Subcommittee B01.04 on
(0.025 mm) greater than a size listed in Table 1, but less than
Conductors of Copper and Copper Alloys.
that of the next larger size, the requirements of the next larger
Current edition approved Sept. 1, 2014. Published September 2014. Originally
approved in 2010. Last previous edition approved in 2010 as B971 – 10. DOI:
size shall apply. No requirements for tensile strength are
10.1520/B0971-10R14.
specified.
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 Available from National Technical Information Service (NTIS), 5285 Port
the ASTM website. Royal Rd., Springfield, VA 22161, http://www.ntis.gov.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
B971−10 (2014)
A
TABLE 1 Tensile Properties TABLE 3 Permissible Variations in Thickness
Equivalent Area at 20°C Elongation in 10
Nominal Thickness Tolerance,
Round in.,
Range, Inch (mm) Inch (mm)
Diameter, in. min, %
cmils in.
0.0010 to 0.0014 +/- 0.0002
0.0641 4 110 0.00323 25
(0.025 to 0.036) (0.005)
0.0571 3 260 0.00256 25
0.0015 to 0.0019 +/- 0.0003
0.0508 2 580 0.00203 25
(0.038 to 0.048) (0.008)
0.0453 2 050 0.00161 25
0.0020 to 0.0049 +/- 0.0004
0.0403 1 620 0.00128 25
(0.051 to 0.124) (0.010)
0.0359 1 290 0.00101 25
0.0050 to 0.0100 +/- 0.0005
0.0320 1 020 0.000804 25
(0.127 to 0.254) (0.013)
0.0285 812 0.000638 25
0.0253 640 0.000503 25
0.0226 511 0.000401 25
TABLE 4 Permissible Variations in Width
0.0201 404 0.00317 20
0.0179 320 0.000252 20
Nominal Width Range, Tolerance,
0.0159 253 0.000199 20
Inch (mm) Inch (mm)
0.0142 202 0.000158 20
0.0126 159 0.000125 20
0.0100 to 0.0499 +/- 0.0013
0.0113 128 0.000100 20
(0.254 to 1.27) (0.033)
0.0100 100 0.0000785 20
0.0500 to 0.0699 +/- 0.0015
0.0089 79.2 0.0000622 15
(1.27 to 1.78) (0.038)
0.0080 64.0 0.0000503 15
0.0700 to 0.0999 +/- 0.0020
0.0071 50.4 0.0000396 15
(1.78 to 2.54) (0.051)
0.0063 39.7 0.0000312 15
0.1000 to 0.1249 +/- 0.0030
0.0056 31.4 0.0000246 15
(2.54 to 3.17) (0.076)
0.0050 25.0 0.0000196 15
0.1250 to 0.1500 +/- 0.0040
0.0045 20.2 0.0000159 15
(3.18 to 3.81) (0.102)
0.0040 16.0 0.0000126 15
A
See Explanatory Note 3 for equivalent round calculation.
5.6 Joints—Necessary joints in the wire and rods prior to
finalcoatinganddrawingshallbemadeinaccordancewiththe
best commercial practice. There shall be no uncoated joints in
5.2.2 Class H—The silver-coated copper flat wire in the
the final product.
hard-drawnconditionshallconformtoelongationrequirements
of 1 % minimum to 5 % maximum. The tensile strength shall
5.7 Finish—The coating shall consist of a smooth continu-
be 55,000 psi (379 MPa) minimum.
ouslayer,firmlyadherenttothesurfaceofthecopper.Thewire
shall be free of all imperfections not consistent with the best
5.3 Resistivity (Explanatory Note 4)—The electrical resis-
commercial practice.
tivity of the coated wire at a temperature of 20°C shall not
exceed the values prescribed in Table 2.
6. Test Methods
5.4 Dimensions and Permissible Variations—The flat wire
6.1 Tensile Strength and Elongation (Explanatory Note 6):
sizes shall be expressed as the thickness and width of the wire
6.1.1 The tensile strength, expressed in pounds per square
indecimalfractionsofaninchtothenearest0.0001in.(0.0025
inch, shall be obtained by dividing the maximum load carried
mm). The silver-coated flat wire shall not vary from the
by the specimen during the tension test by the original
specified thickness and width by more than the amounts
cross-sectional area of the specimen. Tensile strength and
specified in Table 3 and Table 4, respectively.
elongation may be determined simultaneously on the same
5.5 Continuity of Coating—The silver coating shall be
specimen.
continuous. The continuity of coating on the flat wire shall be
6.1.2 The elongation shall be determined as the permanent
determined on representative samples taken before braiding
increase in length, expressed in percent of the original length,
applications or insulating. The continuity of coating shall be
due to the wire breaking in tension. The elongation of the flat
determinedbythehydrochloricacid-sodiumpolysulfidetestin
wire may be determined by measurements made between the
accordance with 6.4. Wire whose coating weight corresponds
jawsofthetensiletestingmachine.Thezerolengthshallbethe
to a thickness less than 40 µ in. (0.00004 in.) shall not be
distance between the jaws at the start of the tension test and be
subject to this test (Explanatory Note 5). The thickness of
asnear10in.(254mm)aspracticable.Thefinallengthshallbe
coating shall be determined in accordance withTest MethodA
the distance between the jaws at the time of rupture. The
as prescribed in Appendix X1.
fracture shall be between the jaws of the testing machine and
not closer than 1 in. (25.4 mm) to the jaw.
6.2 Resistivity (Explanatory Note 4)—The electrical resis-
TABLE 2 Electrical Resistivity Requirements
tivity of the material shall be determined in accordance with
Class of Wire Ω·lb/mile TestMethodB193.Thepurchasermayacceptcertificationthat
the wire was drawn from rod stock meeting the international
A 875.20
standard for annealed copper instead of resistivity tests on the
H 902.27
finished wire.
B971−10 (2014)
6.3 Dimensional Measurements—Dimensional measure- action of the sodium polysulfide. Examine the specimen with
mentsforwidthandthicknessshallbemadewithamicrometer the unaided eye (normal spectacles excepted) against a white
caliperequippedwithaverniergraduatedin0.0001in.(0.0025 background. The specimens shall be considered to have failed
mm). Measurements shall be made on at least three places on if,bysuchblackeningexposedcopperisrevealed.Noattention
each unit selected for this test. Any measurement taken shall be paid to blackening within 0.5 in. (12.7 mm) of the cut
exceeding the dimensions and permissible variation require- end.
ments in 5.4 shall constitute failure to meet the dimensional
6.5 Finish—Surface-finishinspectionshallbemadewiththe
conformance criterion.
unaided eye (normal spectacles excepted).
6.4 Continuity of Coating:
6.4.1 Specimens:
7. Inspection
6.4.1.1 Length of Specimens—Test specimens shall each
7.1 General (Explanatory Note 9)—Unless otherwise speci-
have a length of about 6 in. (152 mm).They shall be tagged or
fied in the contract or purchaser order, the manufacturer shall
marked to correspond with the coil, spool, or reel from which
be responsible for the performance of all inspection and test
they were cut.
requirements specified.
6.4.1.2 Treatment of Specimens—Thoroughly clean the
7.1.1 All inspections and tests shall be made at the place of
specimens by immersion in a suitable organic solvent for at
manufacture unless otherwise especially agreed upon between
least 3 min; then remove and wipe dry with a clean, soft cloth
the manufacturer and the purchaser at the time of purchase.
(Caution: See Explanatory Note 7). Keep the specimens thus
7.1.2 The manufacturer shall afford the inspector represent-
cleaned wrapped in a clean, dry cloth until tested. Do not
ing the purchaser all reasonable manufacturer’s facilities to
handle that part of the specimen to be immersed in the test
satisfy him that the material is being furnished in accordance
solution. Take care to avoid abrasion by the cut ends.
with this specification.
6.4.2 Special Solutions:
7.1.3 Unless otherwise agreed upon between the purchaser
6.4.2.1 Sodium Polysulfide Solution (sp gr 1.142)—Make a
and the manufacturer, conformance of the wire to the various
concentrated solution by dissolving sodium sulfide crystals
requirementslistedinSection5shallbedeterminedonsamples
(cp) in distilled water until the solution is saturated at about
taken from each lot of wire presented for acceptance.
21°C, and adding sufficient flowers of sulfur (in excess of 250
7.1.4 The manufacturer shall, if requested prior to
g/L of solution) to provide complete saturation, as shown by
inspection, certify that all wire in the lot was made under such
the presence in the solution of an excess of sulfur after the
conditions that the product as a whole conforms to the
solution has been allowed to stand for at least 24 h. Make the
requirements of this specification as determined by regularly
test solution by diluting a portion of the concentrated solution
made and recorded tests.
with distilled water to a specific gravity of 1.135 to 1.145 at
15.6°C. The sodium polysulfide test solution should have
7.2 Definitions Applicable to Inspection:
sufficient strength to blacken thoroughly a piece of clean
7.2.1 lot—Any amount of wire of one type and size pre-
uncoated copper wire in 5 s.Aportion of the test solution used
sented for acceptance at one time.
for testing samples shall not be considered to be exhausted
7.2.2 Sample—A quantity of production units (coils, reels,
until it fails to blacken a piece of clean copper as described
andsoforth)selectedatrandomfromthelotforthepurposeof
(Explanatory Note 8):
determining conformance of the lot to the requirements of this
6.4.2.2 Hydrochloric Acid Solution (sp gr 1.088)—Dilute
specification.
commercial HCl (sp gr 1.12) with distilled water to a specific
7.2.3 Specimen—Alengthofwireremovedfortestpurposes
gravity of 1.088 measured at 15.6°C. A portion of the HCl
from any individual production unit of the sample.
solution having a volume of 180 mL shall be considered
7.3 Sample Size (Explanatory Note 9)—The number of
exhausted if it fails to remove within 15 s the discoloration of
production units in a sample shall be as follows:
the silver due to the polysulfide immersion.
7.3.1 A full (100 % inspection) will be completed at every
6.4.3 Procedure:
set-up prior to running the order.
6.4.3.1 Immersion in Polysulfide Solution—Immerse a
7.3.2 Forelongation,resistivity,dimensionalmeasurements,
length of at least 4.5 in. (114 mm) from each of the clean
continuity of coating, and thickness of coating determinations,
specimens for 30 s in the sodium polysulfide solution, de-
thesampleshallconsistofsequentialproductionunitsfromthe
scribed in 6.4.2.1, maintained at a temperature between 15.6
lot.
and 21°C.
7.3.3 For surface-finish inspection and for packaging in-
6.4.3.2 Washing—Aftertheimmersion,thoroughlywashthe
spection(whenspecifiedbythepurchaseratthetimeofplacing
specimensincleanwaterandwipedrywithaclean,softcloth.
the order) the sample shall consist of sequential production
6.4.3.3 Immersion in Hydrochloric Acid—After washing,
units from the lot.
immediately immerse the specimen 15 s in the HCl solution
described in 6.4.2.2, thoroughly wash in clean water, and wipe
8. Conformance Criteria (Explanatory Note 9)
dry with a clean, soft cloth.
6.4.3.4 Examination of Specimens—After immersion and 8.1 Any lot of wire, the samples of which comply with the
washing examine the specimens to ascertain if copper exposed conformance criteria of Section 5, shall be considered as
through openings in the silver coating has been blackened by complying to the requirements of this standard. Individual
B971−10 (2014)
production units that fail to meet one or more of the requ
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
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: B971 − 10 B971 − 10 (Reapproved 2014)
Standard Specification for
Silver-Coated Braid and Ribbon Flat Copper Wire intended
for use in Electronic Application
This standard is issued under the fixed designation B971; 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
1.1 This specification covers silver-coated copper braid and ribbon flat wire intended for electronic application (Explanatory
Note 1).
1.2 Two classes of silver-coated braid and ribbon flat copper wire are covered as follows:
1.2.1 Class A—Annealed temper.
1.2.2 Class H—Hard-drawn.
1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only and are not considered standard.
1.3.1 Exceptions—The SI values for density, resistivity, and volume are to be regarded as standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
B1 Specification for Hard-Drawn Copper Wire
B3 Specification for Soft or Annealed Copper Wire
B49 Specification for Copper Rod Drawing Stock for Electrical Purposes
B193 Test Method for Resistivity of Electrical Conductor Materials
B258 Specification for Nominal Diameters and Cross-Sectional Areas of AWG Sizes of Solid Round Wires Used as Electrical
Conductors
2.2 Other Standards:
NBS Handbook 100 Copper Wire Tables
3. Ordering Information
3.1 Orders for material under this specification shall include the following information:
3.1.1 Quantity of each size,
3.1.2 Wire size-thickness and width in inches (see 5.4),
3.1.3 Class of wire (see 1.2),
3.1.4 Type of copper, if special (see 4.2),
3.1.5 Package size (see 10.1),
3.1.6 Special packaging marking, if required, and
3.1.7 Place of inspection (see 7.1).
This test method 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, 2010Sept. 1, 2014. Published May 2010September 2014. Originally approved in 2010. Last previous edition approved in 2010 as B971
– 10. DOI: 10.1520/B0971-10.10.1520/B0971-10R14.
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’sstandard’s Document Summary page on the ASTM website.
Available from National Technical Information Service (NTIS), 5285 Port Royal Rd., Springfield, VA 22161, http://www.ntis.gov.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
B971 − 10 (2014)
4. Material
4.1 The material shall be silver-coated flat wire (Explanatory Note 1) of such quality and purity that the finished product shall
meet the properties and characteristics prescribed in this specification.
4.2 Copper-Base Metal—The base metal shall be copper of such quality and purity that the finished product shall have
properties and characteristics prescribed in this specification.
NOTE 1—Specifications B1, B3, or B49 define copper suitable for use.
5. General Requirements (See Section 8)
5.1 Temper—The silver-coated flat wire conductor shall be provided in either hard-drawn condition (Class H) or annealed
condition (Class A) as agreed upon between the manufacturer and purchaser.
5.2 Tensile and Elongation (Explanatory Note 2):
5.2.1 Class A—The silver-coated copper flat wire in the annealed condition shall conform to the elongation requirements
prescribed in Table 1. See Explanatory Note 3 for equivalent round diameter calculations based on given thickness and width
dimensions for the flat wire. For flat wire whose nominal equivalent round diameter is more than 0.001 in. (0.025 mm) greater than
a size listed in Table 1, but less than that of the next larger size, the requirements of the next larger size shall apply. No requirements
for tensile strength are specified.
5.2.2 Class H—The silver-coated copper flat wire in the hard-drawn condition shall conform to elongation requirements of 1%
1 % minimum to 5% 5 % maximum. The tensile strength shall be 55,000 psi (379 MPa) minimum.
5.3 Resistivity (Explanatory Note 4)—The electrical resistivity of the coated wire at a temperature of 20°C shall not exceed the
values prescribed in Table 2.
5.4 Dimensions and Permissible Variations—The flat wire sizes shall be expressed as the thickness and width of the wire in
decimal fractions of an inch to the nearest 0.0001 in. (0.0025 mm). The silver-coated flat wire shall not vary from the specified
thickness and width by more than the amounts specified in Table 3 and Table 4, respectively.
5.5 Continuity of Coating—The silver coating shall be continuous. The continuity of coating on the flat wire shall be determined
on representative samples taken before braiding applications or insulating. The continuity of coating shall be determined by the
hydrochloric acid-sodium polysulfide test in accordance with 6.4. Wire whose coating weight corresponds to a thickness less than
40 μ in. (0.00004 in.) shall not be subject to this test (Explanatory Note 5). The thickness of coating shall be determined in
accordance with Test Method A as prescribed in Appendix X1.
5.6 Joints—Necessary joints in the wire and rods prior to final coating and drawing shall be made in accordance with the best
commercial practice. There shall be no uncoated joints in the final product.
A
TABLE 1 Tensile Properties
Equivalent Area at 20°C Elongation in 10
Round in.,
Diameter, in. min, %
cmils in.
0.0641 4 110 0.00323 25
0.0571 3 260 0.00256 25
0.0508 2 580 0.00203 25
0.0453 2 050 0.00161 25
0.0403 1 620 0.00128 25
0.0359 1 290 0.00101 25
0.0320 1 020 0.000804 25
0.0285 812 0.000638 25
0.0253 640 0.000503 25
0.0226 511 0.000401 25
0.0201 404 0.00317 20
0.0179 320 0.000252 20
0.0159 253 0.000199 20
0.0142 202 0.000158 20
0.0126 159 0.000125 20
0.0113 128 0.000100 20
0.0100 100 0.0000785 20
0.0089 79.2 0.0000622 15
0.0080 64.0 0.0000503 15
0.0071 50.4 0.0000396 15
0.0063 39.7 0.0000312 15
0.0056 31.4 0.0000246 15
0.0050 25.0 0.0000196 15
0.0045 20.2 0.0000159 15
0.0040 16.0 0.0000126 15
A
See Explanatory Note 3 for equivalent round calculation.
B971 − 10 (2014)
TABLE 2 Electrical Resistivity Requirements
Class of Wire Ω·lb/mile
A 875.20
H 902.27
TABLE 3 Permissible Variations in Thickness
Nominal Thickness Tolerance,
Range, Inch (mm) Inch (mm)
0.0010 to 0.0014 +/- 0.0002
(0.025 to 0.036) (0.005)
0.0015 to 0.0019 +/- 0.0003
(0.038 to 0.048) (0.008)
0.0020 to 0.0049 +/- 0.0004
(0.051 to 0.124) (0.010)
0.0050 to 0.0100 +/- 0.0005
(0.127 to 0.254) (0.013)
TABLE 4 Permissible Variations in Width
Nominal Width Range, Tolerance,
Inch (mm) Inch (mm)
0.0100 to 0.0499 +/- 0.0013
(0.254 to 1.27) (0.033)
0.0500 to 0.0699 +/- 0.0015
(1.27 to 1.78) (0.038)
0.0700 to 0.0999 +/- 0.0020
(1.78 to 2.54) (0.051)
0.1000 to 0.1249 +/- 0.0030
(2.54 to 3.17) (0.076)
0.1250 to 0.1500 +/- 0.0040
(3.18 to 3.81) (0.102)
5.7 Finish—The coating shall consist of a smooth continuous layer, firmly adherent to the surface of the copper. The wire shall
be free of all imperfections not consistent with the best commercial practice.
6. Test Methods
6.1 Tensile Strength and Elongation (Explanatory Note 6):
6.1.1 The tensile strength, expressed in pounds per square inch, shall be obtained by dividing the maximum load carried by the
specimen during the tension test by the original cross-sectional area of the specimen. Tensile strength and elongation may be
determined simultaneously on the same specimen.
6.1.2 The elongation shall be determined as the permanent increase in length, expressed in percent of the original length, due
to the wire breaking in tension. The elongation of the flat wire may be determined by measurements made between the jaws of
the tensile testing machine. The zero length shall be the distance between the jaws at the start of the tension test and be as near
10 in. (254 mm) as practicable. The final length shall be the distance between the jaws at the time of rupture. The fracture shall
be between the jaws of the testing machine and not closer than 1 in. (25.4 mm) to the jaw.
6.2 Resistivity (Explanatory Note 4)—The electrical resistivity of the material shall be determined in accordance with Test
Method B193. The purchaser may accept certification that the wire was drawn from rod stock meeting the international standard
for annealed copper instead of resistivity tests on the finished wire.
6.3 Dimensional Measurements—Dimensional measurements for width and thickness shall be made with a micrometer caliper
equipped with a vernier graduated in 0.0001 in. (0.0025 mm). Measurements shall be made on at least three places on each unit
selected for this test. Any measurement taken exceeding the dimensions and permissible variation requirements in 5.4 shall
constitute failure to meet the dimensional conformance criterion.
6.4 Continuity of Coating:
6.4.1 Specimens:
6.4.1.1 Length of Specimens—Test specimens shall each have a length of about 6 in. (152 mm). They shall be tagged or marked
to correspond with the coil, spool, or reel from which they were cut.
6.4.1.2 Treatment of Specimens—Thoroughly clean the specimens by immersion in a suitable organic solvent for at least 3 min;
then remove and wipe dry with a clean, soft cloth (Caution: See Explanatory Note 7). Keep the specimens thus cleaned wrapped
in a clean, dry cloth until tested. Do not handle that part of the specimen to be immersed in the test solution. Take care to avoid
abrasion by the cut ends.
B971 − 10 (2014)
6.4.2 Special Solutions:
6.4.2.1 Sodium Polysulfide Solution (sp gr 1.142)—Make a concentrated solution by dissolving sodium sulfide crystals (cp) in
distilled water until the solution is saturated at about 21°C, and adding sufficient flowers of sulfur (in excess of 250 g/L of solution)
to provide complete saturation, as shown by the presence in the solution of an excess of sulfur after the solution has been allowed
to stand for at least 24 h. Make the test solution by diluting a portion of the concentrated solution with distilled water to a specific
gravity of 1.135 to 1.145 at 15.6°C. The sodium polysulfide test solution should have sufficient strength to blacken thoroughly a
piece of clean uncoated copper wire in 5 s. A portion of the test solution used for testing samples shall not be considered to be
exhausted until it fails to blacken a piece of clean copper as described (Explanatory Note 8):
6.4.2.2 Hydrochloric Acid Solution (sp gr 1.088)—Dilute commercial HCl (sp gr 1.12) with distilled water to a specific gravity
of 1.088 measured at 15.6°C. A portion of the HCl solution having a volume of 180 mL shall be considered exhausted if it fails
to remove within 15 s the discoloration of the silver due to the polysulfide immersion.
6.4.3 Procedure:
6.4.3.1 Immersion in Polysulfide Solution—Immerse a length of at least 4.5 in. (114 mm) from each of the clean specimens for
30 s in the sodium polysulfide solution, described in 6.4.2.1, maintained at a temperature between 15.6 and 21°C.
6.4.3.2 Washing—After the immersion, thoroughly wash the specimens in clean water and wipe dry with a clean, soft cloth.
6.4.3.3 Immersion in Hydrochloric Acid—After washing, immediately immerse the specimen 15 s in the HCl solution described
in 6.4.2.2, thoroughly wash in clean water, and wipe dry with a clean, soft cloth.
6.4.3.4 Examination of Specimens—After immersion and washing examine the specimens to ascertain if copper exposed
through openings in the silver coating has been blackened by action of the sodium polysulfide. Examine the specimen with the
unaided eye (normal spectacles excepted) against a white background. The specimens shall be considered to have failed if, by such
blackening exposed copper is revealed. No attention shall be paid to blackening within 0.5 in. (12.7 mm) of the cut end.
6.5 Finish—Surface-finish inspection shall be made with the unaided eye (normal spectacles excepted).
7. Inspection
7.1 General (Explanatory Note 9)—Unless otherwise specified in the contract or purchaser order, the manufacturer shall be
responsible for the performance of all inspection and test requirements specified.
7.1.1 All inspections and tests shall be made at the place of manufacture unless otherwise especially agreed upon between the
manufacturer and the purchaser at the time of purchase.
7.1.2 The manufacturer shall afford the inspector representing the purchaser all reasonable manufacturer’s facilities to satisfy
him that the material is being furnished in accordance with this specification.
7.1.3 Unless otherwise agreed upon between the purchaser and the manufacturer, conformance of the wire to the various
requirements listed in Section 5 shall be determined on samples taken from each lot of wire presented for acceptance.
7.1.4 The manufacturer shall, if requested prior to inspection, certify that all wire in the lot was made under such conditions
that the product as a whole conforms to the requirements of this specification as determined by regularly made and recorded tests.
7.2 Definitions Applicable to Inspection:
7.2.1 lot—Any amount of wire of one type and size presented for acceptance at one time.
7.2.2 Sample—A quantity of production units (coils, reels, and so forth) selected at random from the lot for the purpose of
determining conformance of the lot to the requirements of this specification.
7.2.3 Specimen—A length of wire removed for test purposes from any individual production unit of the sample.
7.3 Sample Size (Explanatory Note 9)—The number of production units in a sample shall be as follows:
7.3.1 A full (100 % inspection) will be completed at every set-up prior to running the order.
7.3.2 For elongation, resistivity, dimensional measurements, continuity of coating, and thickness of coating de
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