ASTM B786-08

This document is not anASTM standard and is intended only to provide the user of anASTM 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:B 786–02a Designation: B 786 – 08
Standard Specification for
19 Wire Combination Unilay-Stranded Aluminum
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Conductors for Subsequent Insulation
This standard is issued under the fixed designation B 786; 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 bare combination unilay-stranded conductors made from round wires of aluminum 1350 and 8000
series of aluminum alloys, for insulated conductors for electrical purposes. Aluminum 1350 wires in tempers -H19 (extra hard),
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-H16 or -H26 ( ⁄4 hard), -H14 or -H24 ( ⁄2 hard), and -H142 or -H242 ( ⁄2 hard) and 8000 series aluminum alloys wires in tempers
“0” and H1X or H2X are permitted. These conductors shall be constructed with a central core wire surrounded by two layers of
helically laid wires, resulting in an outer diameter equal to the compressed-stranded equivalent conductors.
NOTE 1—For the purpose of this specification, combination unilay conductor is defined as follows: a central core wire surrounded by a layer of six
helically laid wires of the same diameter as the core wire with a helically laid outer layer containing six smaller wires alternated between six wires of
the same diameter as the wires in the layer underneath. Both layers have a common length and direction of lay (see Fig. 1).
1.1.1 For the purpose of this specification, normal conductor classification (Class AA, A, B, C) is not applicable, as these
conductors are intended for subsequent insulation. The descriptive term combination unilay-stranded shall be used in place of
conductor classification (Note 2 and Note 3).
NOTE 2—Prior to 1975, aluminum 1350 was designated as EC aluminum.
NOTE 3—The aluminum and temper designations conform to ANSI Standard H35.1. Aluminum 1350 corresponds to Unified Numbering System
A91350 in accordance with Practice E 527. Unified Numbering System alloy designations for 8000 Series aluminum alloys in accordance with Practice
E 527 are listed in Table number 1 of Specification B 800.
1.2The values stated in inch-pound or SI units are to be regarded separately as standard.The values in each system are not exact
equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result
in nonconformance with the specification.
1.2.1For density, resistivity and temperature, the values stated in SI units are to be regarded as standard.
1.2 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.
2. Referenced Documents
2.1 The following documents of the issue in effect on date of material purchase form a part of this specification to the extent
referenced herein.
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2.2 ASTM Standards:
B 193 Test Method for Resistivity of Electrical Conductor Materials
B 230/B 230M Specification for Aluminum 1350-H191350H19 Wire for Electrical Purposes
B 263 Test Method for Determination of Cross-Sectional Area of Stranded Conductors
B 609/B 609M Specification for Aluminum 1350 Round Wire, Annealed and Intermediate Tempers, for Electrical Purposes
B 800 Specification for 8000 Series Aluminum Alloy Wire for Electrical Purposes—Annealed and Intermediate Tempers
B 801 Specification for Concentric-Lay-Stranded Conductors of 8000 Series Aluminum Alloy for Subsequent Covering or
Insulation
E 29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
E 527Practice for Numbering Metals andAlloys (UNS) Practice for Numbering Metals andAlloys in the Unified Numbering
System (UNS)
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This specification is under the jurisdiction of ASTM Committee B01 on Electrical Conductors and is the direct responsibility of Subcommittee B01.07 on Conductors
of Light Metals.
Current edition approved Oct. 10, 2002.Sept. 1, 2008. Published Decemeber 2002.October 2008. Originally approved in 1988. Last previous edition approved in 2002 as
B 786 – 02a.
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, Vol 02.03.volume information, refer to the standard’s Docu
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