ASTM E8/E8M-16a pdf free.Standard Test Methods for Tension Testing of Metallic Materials.
These test methods cover the tension testing of metallic materials in any form at room temperature, specifically, the methods of determination of yield strength, yield point elongation, tensile strength, elongation, and reduction of area.
5. Apparatus
5.1 Testing Machines-Machines used for tension testing shall conform to the requirements of Practices E4. 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, Where verification of the testing machine speed is required, Practices E2658 shall be used unless otherwise specified.
5.2 Gripping Devices
5.2.1 General-Various types of gripping devices may be used to transmit the measured force applied by the testing machine to the test specimens. 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).
6. Test Specimens
6.1 General:
6.1.1 Specimen Size-Test specimens shall be either sub- stantially full size or machined, as prescribed in the product specifications for the material being tested.
6.1.2 Location-Unless otherwise specified. the axis of the test specimen shall be located within the parent material as follows
6.1.2.1 At the center for products 40 mm [1.500 in.] or less
thickness diameter. or distance between flats.
6.1.2.2 Midway from the center to the surface for products over 40 mm [1.500 in.] in thickness, diameter, or distance between flats
6.1.3 Specimen Machining-Improperly prepared test speci mens often are the reason for unsatisfactory and incorrect test results. It is important, therefore, that care be exercised in the preparation of specimens, particularly in the machining, to maximize precision and minimize bias in test results.
6. 1.3.I The reduced section including the fillets of prepared pecimens should be free of cold work, notches, chatter mark grooves, gouges, burrs, rough surfaces or edges, overheating. or any other condition which can deleteriously affect the properties to be measured.ASTM E8/E8M-16a pdf free.