ASTM D5621 - 07(2013)

    Standard Test Method for Sonic Shear Stability of Hydraulic Fluids

    Active Standard ASTM D5621 | Developed by Subcommittee: D02.07

    Book of Standards Volume: 05.02


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    ASTM D5621

    Significance and Use

    4.1 This test method was developed using Test Method D2603–91.

    4.2 This test method permits the evaluation of shear stability with minimum interference from thermal and oxidative factors that may be present in some applications. It has been found applicable to fluids containing both readily sheared and shear-resistant polymers. Correlation with performance in the case of hydraulic applications has been established.

    1. Scope

    1.1 This test method covers the evaluation of the shear stability of hydraulic fluids in terms of the final viscosity that results from irradiating a sample of the hydraulic fluid in a sonic oscillator.

    1.2 Evidence has been presented that a good correlation exists between the shear degradation that results from sonic oscillation and that obtained in a vane pump test procedure.2

    1.3 This test method uses millimetres squared per second (mm2/s), an SI unit, as the unit of viscosity. For information, the equivalent unit, cSt, is shown in parentheses.

    1.4 This standard does not purport to address all of the safety concerns, 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

    D445 Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity)

    D2603 Test Method for Sonic Shear Stability of Polymer-Containing Oils

    D6022 Practice for Calculation of Permanent Shear Stability Index


    ICS Code

    ICS Number Code 75.120 (Hydraulic fluids)

    UNSPSC Code

    UNSPSC Code 15121504(Hydraulic oil)


    DOI: 10.1520/D5621

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