ASTM D790-15

    Standard Test Methods for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials


      Format Pages Price  
    PDF 12 $67.00   ADD TO CART


    1. Scope

    1.1 These test methods are used to determine the flexural properties of unreinforced and reinforced plastics, including highmodulus composites and electrical insulating materials utilizing a three-point loading system to apply a load to simply supported beam (specimen). The method is generally applicable to both rigid and semi-rigid materials, but flexural strength cannot be determined for those materials that do not break or that do not fail yield in the outer surface of the test specimen within the 5.0 % strain limit.

    1.2 Test specimens of rectangular cross section are injection molded or, cut from molded or extruded sheets or plates, or cut from molded or extruded shapes. Specimens must be solid and uniformly rectangular. The specimen rests on two supports and is loaded by means of a loading nose midway between the supports.

    1.3 Measure deflection in one of two ways; using crosshead position or a deflectometer. Please note that studies have shown that deflection data obtained with a deflectometer will differ from data obtained using crosshead position. The method of deflection measurement shall be reported.

    Note 1: Requirements for quality control in production environments are usually met by measuring deflection using crosshead position. However, more accurate measurement may be obtained by using an deflection indicator such as a deflectometer.

    Note 2: Materials that do not rupture by the maximum strain allowed under this test method may be more suited to a 4-point bend test. The basic difference between the two test methods is in the location of the maximum bending moment and maximum axial fiber stresses. The maximum axial fiber stresses occur on a line under the loading nose in 3-point bending and over the area between the loading noses in 4-point bending. A four-point loading system method can be found in Test Method D6272.

    1.4 The values stated in SI units are to be regarded as the standard. The values provided in parentheses are for information only.

    1.5 The text of this standard references notes and footnotes that provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the standard.

    1.6 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.

    Note 3: This standard and ISO 178 address the same subject matter, but differ in technical content.


    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

    D618 Practice for Conditioning Plastics for Testing

    D638 Test Method for Tensile Properties of Plastics

    D883 Terminology Relating to Plastics

    D4000 Classification System for Specifying Plastic Materials

    D4101 Specification for Polypropylene Injection and Extrusion Materials

    D5947 Test Methods for Physical Dimensions of Solid Plastics Specimens

    D6272 Test Method for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials by Four-Point Bending

    E4 Practices for Force Verification of Testing Machines

    E83 Practice for Verification and Classification of Extensometer Systems

    E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method

    E2309 Practices for Verification of Displacement Measuring Systems and Devices Used in Material Testing Machines


    ICS Code

    ICS Number Code 29.035.20 (Plastic and rubber insulating materials)

    UNSPSC Code

    UNSPSC Code 13100000(Rubber and elastomers); 39121721(Electrical insulators)


    Referencing This Standard
    Link Here
    Link to Active (This link will always route to the current Active version of the standard.)

    DOI: 10.1520/D0790-15

    Citation Format

    ASTM D790-15, Standard Test Methods for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials, ASTM International, West Conshohocken, PA, 2015, www.astm.org

    Back to Top