Designation: D 6272 – 02Standard Test Method forFlexural Properties of Unreinforced and Reinforced Plasticsand Electrical Insulating Materials by Four-Point Bending 1This standard is issued under the fixed designation D 6272; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e ) indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers the determination of flexuralproperties of unreinforced and reinforced plastics, includinghigh-modulus composites and electrical insulating materials inthe form of rectangular bars molded directly or cut from sheets,plates, or molded shapes. These test methods are generallyapplicable to rigid and semirigid materials. However, flexuralstrength cannot be determined for those materials that do notbreak or that do not fail in the outer fibers. This test methodutilizes a four point loading system applied to a simplysupported beam.1.2 This test method may be used with two procedures:1.2.1 Procedure A, designed principally for materials thatbreak at comparatively small deflections.1.2.2 Procedure B, designed particularly for those materialsthat undergo large deflections during testing.1.2.3 Procedure A shall be used for measurement of flexuralproperties, particularly flexural modulus, unless the materialspecification states otherwise. Procedure B may be used formeasurement of flexural strength.1.3 Comparative tests may be run according to eitherprocedure, provided that the procedure is found satisfactory forthe material being tested.1.4 The values stated in SI units are to be regar...