AHM E8/E8M – 13a. G–Gauge length. Dimensions, mm [in.] For Test Specimens with Gauge Length Four times the Diameter (E8]. Standard. Small-Size. Buy ASTM E 8/E8M: A TEST METHODS FOR TENSION TESTING OF METALLIC MATERIALS from SAI Global. Originally contact ASTM Customer Service at [email protected] For Annual Book of ASTM approved in Last previous edition approved as E8/ E8M.
A number in parentheses indicates the year of last reapproval. A superscript epsilon indicates an editorial change since the last revision or reapproval. The gauge length is the most significant difference between E8 and E8M test specimens. The values stated in each system are not exact equivalents; therefore each system must be used independently of the other. Combining values from the two systems may result in non-conformance with the standard. It is the responsibility of the user of this standard to establish appropriate safety and health practices r8m determine the applicability of regulatory limitations prior to use.
Current edition approved May 1, Originally approved in No further reproductions authorized.
Such interpretation is usually applicable to values for reduction of area reported in the literature when no further qualification is given. This information may be useful in comparisons of materials, alloy development, quality control, and design under certain circumstances.
The test methods have been used extensively in the trade for this purpose. The forces used in determining tensile strength and yield strength shall be within the verified force application range of the testing machine as defined in Practices E4.
ASTM E8.E8M -15-Tensiont testing of metallic materials
To ensure axial tensile stress within the gauge length, the axis of the test specimen should coincide with the center line of the heads of the testing machine.
Any departure from this requirement may introduce bending stresses that are not included in the usual stress computation force divided by cross-sectional area. NOTE 1—The effect of this eccentric force application may be illustrated by calculating the bending moment and stress thus added. For a standard This error increases to 2.
These wedge grips generally furnish a satisfactory means of gripping long specimens of ductile metal. If, however, for any reason, one grip of a pair advances farther than the other as the grips tighten, an undesirable bending stress may be introduced.
When liners are used behind the wedges, they must be of the same thickness and their faces must be flat and parallel. For best results, the wedges should be supported over their entire lengths by the heads of the testing machine.
This requires that liners of several thicknesses be available to cover the range of specimen thickness. For proper gripping, it is desirable that the entire length of the serrated face of each wedge be in contact with the specimen. Proper alignment of wedge grips and liners is illustrated in Fig.
For short specimens and for specimens of many materials it is generally necessary to use machined test specimens and to use a special means of gripping to ensure that the specimens, when under load, shall be as nearly as possible in uniformly distributed pure axial tension see 5. Brittle Materials—A schematic diagram of e8j gripping device for threaded-end specimens is shown in Fig. Both of these gripping devices should be attached to the heads of the testing machine through properly lubricated sphericalseated bearings.
The distance between spherical bearings should be as great as feasible. Extensometers shall be used and verified to include the strains corresponding to the yield strength and elongation at fracture if determined. For measuring elongation at fracture with an appropriate extensometer, the gauge length of the extensometer shall be equal to the nominal gauge length required for the specimen being tested.
It is important, therefore, that care be exercised atm the preparation of specimens, particularly in the machining, to maximize precision and minimize bias in test results.
ASTM E8.E8M Tensiont testing of metallic materials –
NOTE 3—Punching or blanking of the reduced section may produce significant cold work or shear burrs, or both, along the edges which should be removed by machining. For this reason, a small taper is permitted in the reduced section of each of the specimens described in the following sections.
E8M Tensiont testing of metallic materials Juliano row Enviado por: Parte 1 de 8 Designation: Astm a Astm a Astm c astm normas fibra de vidrio.
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