ASTM B491/B491M-00

    Historical Standard: ASTM B491/B491M-00 Standard Specification for Aluminum and Aluminum-Alloy Extruded Round Tubes for General-Purpose Applications

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    ASTM B491 / B491M

    1. Scope

    1.1 This specification covers aluminum and aluminum-alloy extruded round tubes either in coils or straight lengths, for general purpose applications such as refrigeration service, gas lines, oil lines, and instrument lines, in the alloys (Note 2) and tempers shown in Table 2 [2M], in outside diameters of 0.250 through 0.750 in. [6.00 through 20.00 mm]. For diameters over 0.500 through 0.750 in. [over 12.50 through 20.00 mm], the diameter and wall-thickness tolerances and eddy-current test parameters, if required, shall be agreed upon by the producer and the purchaser. Only tubes in aluminum 1200-H111 and 1235-H111 are sized after extrusion to minimize ovalness.

    1.2 Alloy and temper designations are in accordance with ANSI H35.1 [H35.1M]. The equivalent Unified Numbering System alloy designations are those of Table 1 preceded by A9 (for example, A91050 for aluminum 1050) in accordance with Practice E527.

    Note 1-For extruded tubes see Specification B221, and for drawn tubes for general-purpose applications see Specification B483. Note 2-Throughout this specification the term alloy in the general sense includes aluminum as well as aluminum alloy. Note 3-For inch-pound orders specify B491; for metric orders specify B491M. Do not mix units.

    1.3 For acceptance criteria for inclusion of new aluminum and aluminum alloys in this specification, see Annex A2.

    1.4 The values stated in either inch-pound or SI units are to be regarded separately as standards. The SI units are shown either in brackets or in separate tables. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values from two systems will result in nonconformance with the specification.


    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

    B557 Test Methods for Tension Testing Wrought and Cast Aluminum- and Magnesium-Alloy Products

    B557M Test Methods for Tension Testing Wrought and Cast Aluminum- and Magnesium-Alloy Products (Metric)

    B660 Practices for Packaging/Packing of Aluminum and Magnesium Products

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

    B881 Terminology Relating to Aluminum- and Magnesium-Alloy Products

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

    E34 Test Methods for Chemical Analysis of Aluminum and Aluminum-Base Alloys

    E55 Practice for Sampling Wrought Nonferrous Metals and Alloys for Determination of Chemical Composition

    E215 Practice for Standardizing Equipment for Electromagnetic Testing of Seamless Aluminum-Alloy Tube

    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 Spectrochemical Analysis

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

    ANSI Standards

    H35.2M Dimensional Tolerances for Aluminum Mill Products (Metric)

    Federal Standard

    Fed.Std.No.123 Marking for Shipment (Civil Agencies) Available from Standardization Documents Order Desk, DODSSP, Bldg. 4, Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098.

    Military Standard

    MIL-STD-129 Marking for Shipment and Storage


    ICS Code

    ICS Number Code 23.040.15 (Non-ferrous metal pipes)

    UNSPSC Code

    UNSPSC Code 40182700(Extruded aluminum tubes); 30102306(Aluminum profiles)


    DOI: 10.1520/B0491_B0491M-00

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