ASTM E8/E8M test method determines the response of metallic materials to tension testing at room temperature between 10 and 38°C. It also determines yield strength, yield point elongation, tensile strength, elongation and area reduction with the gauge lengths for the specimens E8 and E8M to be fixed at 4D and 5D, respectively. The results are expressed in SI units.
ASTM E8/E8M test method defines a standard for the industrial use of metallic materials by performing tension testing. Tension testing is effective in determining the strength and ductility of materials under tensile stress. It contributes towards the alloy development, quality control and designing of the materials along with setting the comparison standards. This method helps make decisions regarding the acceptance of materials and their commercial shipment and trade.
The test machine is prepared to function at a normal operating temperature, and the dimensions of the test specimen are considered. The cross-sectional area and weight of the specimen are determined and zeroing of the testing machine is performed. The specimen is gripped and the speed of testing is determined and controlled. Along with the determination of yield properties, elongation takes place. The data obtained is rounded off to obtain the yield strength and tensile strength.
The sample’s length, width, and thickness should be 55 mm, 10 mm, and 10 mm, respectively.
Rate of straining is maintained at 0.015 ± 0.006 mm/min and yield strength is calculated by the help of stress-strain diagram as follows: