ASTM B520-12

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Designation:B520 −12
Standard Specification for
Tin-Coated, Copper-Clad Steel Wire for Electronic
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Application
This standard is issued under the fixed designation B520; 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.
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1. Scope 2.2 ASTM Standards:
B193 Test Method for Resistivity of Electrical Conductor
1.1 This specification covers tin-coated copper-clad steel
Materials
wire for electronic application.
B258 Specification for Nominal Diameters and Cross-
SectionalAreasofAWGSizesofSolidRoundWiresUsed
1.2 Four classes of tin-coated copper-clad steel wire are
as Electrical Conductors
covered as follows:
B452 Specification for Copper-Clad Steel Wire for Elec-
1.2.1 Class T30HS—Nominal 30 % conductivity, hard-
tronic Application
drawn,
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2.3 National Institute of Standards and Technology:
1.2.2 Class T30A—Nominal 30 % conductivity, annealed,
NBS Handbook 100 Copper Wire Tables
1.2.3 Class T40HS—Nominal 40 % conductivity, hard-
drawn, and
3. Ordering Information
1.2.4 Class T40A—Nominal 40 % conductivity, annealed.
3.1 Orders for material under this specification shall include
the following information:
1.3 The values stated in inch-pound units are to be regarded
3.1.1 Quantity of each size.
as standard. The values given in parentheses are mathematical
3.1.2 Wire size (see 5.3 and Table 1),
conversions to SI units that are provided for information only
3.1.3 Class of wire (see 1.2),
and are not considered standard.
3.1.4 Package size and shipping (see 7.1.7 and Section 9),
1.3.1 Exception—The SI values for resistivity and volume
packaging inspection if required (see 9.3.3),
are to be regarded as standard.
3.1.5 Special package marking, if required, and
3.1.6 Place of inspection (see 9.1).
1.4 The following safety hazards caveat pertains only to the
test method portion, Section 6, of this specification: This
4. Material
standard does not purport to address all of the safety concerns,
if any, associated with its use. It is the responsibility of the user 4.1 Thebasismaterialshallconsistofcopper-cladsteelwire
of this standard to establish appropriate safety and health conforming to the product description, quality and specifica-
tion requirements of Specification B452.
practices and determine the applicability of regulatory limita-
tions prior to use.(Warning—Consideration should be given
4.2 Thetin-coatedwireshallconsistofthebasiswirecoated
to toxicity and flammability when selecting solvent cleaners.)
with tin. The tin used for coating shall be commercially pure
(Note 1). For purposes of this specification, the tin shall be
2. Referenced Documents
considered“ commercially pure” if the total of other elements,
exclusive of copper, does not exceed 1 %. Notwithstanding the
2.1 The following documents of the issue in effect on date
previoussentence,chemicalanalysisofthetincoatingorofthe
of material purchase form a part of this specification to the
tin used for coating shall not be required under this specifica-
extent referenced herein:
tion.Adequacyofthetincoatingisassuredbythecontinuityof
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This specification is under the jurisdiction of ASTM Committee B01 on For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Electrical Conductors and is the direct responsibility of Subcommittee B01.06 on contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Bi-Metallic Conductors. Standards volume information, refer to the standard’ Document Summary page on
Current edition approved Oct. 15, 2012. Published November 2012. Originally the ASTM website.
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approved in 1970. Last previous edition approved in 2007 as B520 – 93 (2007). Available from National Institute of Standards and Technology (NIST), 100
DOI: 10.1520/B0520-12. Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http://www.nist.gov.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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B520−12
TABLE 1 Wire Sizes TABLE 2 Resistivity, max at 20°C
Diameter Cross-Sectional Area at 20°C (68°F) Class of Nominal Diameter, in.
2
Ω·mm /m
Wire (mm)
2 2
in. mm cmil in. mm
T30HS 0.0720 (1.829) to 0.06743
0.0720 1.8129 5180 0.00407 2.63
0.0201 (0.511) incl (0.067427)
0.0641 1.6128 4110 0.00323 2.08
and under 0.0201 (0.511) to 0.07315
0.0571 1.450 3260 0.00256 1.65
0.0113 (0.287) incl (0.073148)
0.0508 1.290 2580 0.00203 1.31
T30A under 0.0113 (0.287) to 0.07642
0.0453 1.151 2050 0.00161 1.04
0.0031 (0.079) incl (0.076423)
0.0403 1.024 162
...