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    ASTM B373 - 19

    Standard Specification for Aluminum Foil for Capacitors

    Active Standard ASTM B373 | Developed by Subcommittee: B07.03

    Book of Standards Volume: 02.02

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    This specification covers nine thicknesses of annealed aluminum foil for use in manufacture of capacitors and includes UNS alloy designations A91145 and A91235. Foil to be used as anodes in electrolytic capacitors is beyond the scope of this specification. Requirements for quality assurance, chemical analysis, and tensile breaking load test are detailed. The foil shall conform to the chemical composition requirements prescribed for aluminum, silicon and iron, copper, manganese, magnesium, zinc, vanadium, and titanium, and shall meet the specified requirements for tensile breaking load, direct current electrical resistance, and area per unit weight. The foil shall be supplied with the finish bright on one side and matte on the other, in the dry or slick condition (dry annealed A, dry annealed B, dry annealed C, or slick annealed) and shall be tested for surface condition by water or water-alcohol test. Spooling requirements such as roll dimensions, roll winding, and roll covering are given. Foil splices shall be either welded or knurled and shall be free of splits, slivers, wrinkles, ragged edges, or excessive pinholes.

    This abstract is a brief summary of the referenced standard. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.

    1. Scope

    1.1 This specification covers nine thicknesses (0.00017 to 0.00050 in. (0.0043 to 0.0127 mm)) of annealed aluminum foil used in the manufacture of capacitors.

    1.2 Foil to be used as anodes in electrolytic capacitors is beyond the scope of this specification.

    1.3 Alloy designations are in accordance with ANSI H35.11/H35.1(M). The equivalent Unified Numbering System alloy designations are those of Table 1 preceded by A9, for example, A91145 for Aluminum 1145 in accordance with Practice E527.

    1.4 For acceptance criteria for inclusion of new aluminum and aluminum alloys in this specification, see Annex A1.

    1.5 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.

    1.6 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 (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

    ASTM Standards

    B193 Test Method for Resistivity of Electrical Conductor Materials

    B666/B666M Practice for Identification Marking of Aluminum and Magnesium Products

    B881 Terminology Relating to Aluminum- and Magnesium-Alloy Products

    B985 Practice for Sampling Aluminum Ingots, Billets, Castings and Finished or Semi-Finished Wrought Aluminum Products for Compositional Analysis

    E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications

    E252 Test Method for Thickness of Foil, Thin Sheet, and Film by Mass Measurement

    E345 Test Methods of Tension Testing of Metallic Foil

    E527 Practice for Numbering Metals and Alloys in the Unified Numbering System (UNS)

    E607 Test Method for Atomic Emission Spectrometric Analysis Aluminum Alloys by the Point to Plane Technique Nitrogen Atmosphere

    E716 Practices for Sampling and Sample Preparation of Aluminum and Aluminum Alloys for Determination of Chemical Composition by Spark Atomic Emission Spectrometry

    E1251 Test Method for Analysis of Aluminum and Aluminum Alloys by Spark Atomic Emission Spectrometry

    Other Standards

    CEN EN 14242 Aluminum and aluminum alloys. Chemical analysis. Inductively coupled plasma optical emission spectral analysis

    UNSPSC Code

    UNSPSC Code 30102006(Aluminum foil); 32121500(Capacitors)

    Referencing This Standard
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    DOI: 10.1520/B0373-19

    Citation Format

    ASTM B373-19, Standard Specification for Aluminum Foil for Capacitors, ASTM International, West Conshohocken, PA, 2019, www.astm.org

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