ASTM E930 - 99(2007)

    Standard Test Methods for Estimating the Largest Grain Observed in a Metallographic Section (ALA Grain Size)

    Active Standard ASTM E930 | Developed by Subcommittee: E04.08

    Book of Standards Volume: 03.01


    Buy Standard (PDF)
    6 pages
    $42.00
    Buy Standard (Print)
    6 pages
    $42.00

    Historical (view previous versions of standard)


    ASTM E930

    Significance and Use

    The presence of large grains has been correlated with anomalous mechanical behavior in, for example, crack initiation, crack propagation, and fatigue. Thus there is engineering justification for reporting the ALA grain size.

    These methods shall only be used with the presence of outlier coarse grains, 3 or more ASTM grain size numbers larger than the rest of the microstructure and comprising 5 % or less of the specimen area. A typical example is shown in Annex A1 as Fig. A1.1.

    These methods shall not be used for the determination of average grain size, which is treated in Test Methods E 112. Examples of microstructures that do not qualify for ALA treatment are shown in Annex A1 as Fig. A1.2, Fig. A1.3, and Fig. A1.4.

    These methods may be applied in the characterization of duplex grain sizes, as instructed in the procedures for Test Methods E 1181.

    1. Scope

    1.1 These test methods describe simple manual procedures for measuring the size of the largest grain cross-section observed on a metallographically prepared plane section.

    1.2 These test methods shall only be valid for microstructures containing outlier coarse grains, where their population is too sparse for grain size determination by Test Methods E 112.

    1.3 This standard does not purport to address all of the safety problems, 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 (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

    ASTM Standards

    E3 Guide for Preparation of Metallographic Specimens

    E7 Terminology Relating to Metallography

    E112 Test Methods for Determining Average Grain Size

    E407 Practice for Microetching Metals and Alloys

    E1181 Test Methods for Characterizing Duplex Grain Sizes


    ICS Code

    ICS Number Code 19.120 (Particle size analysis. Sieving)

    UNSPSC Code

    UNSPSC Code


    DOI: 10.1520/E0930-99R07

    ASTM International is a member of CrossRef.

    ASTM E930

    Citing ASTM Standards
    Back to Top