The ASTM E21 standard describes the single-axis elevated temperature tension test/hot tensile test on metallic materials. The test is used to determine characteristic values including tensile strength, yield point, offset yield, strain at break and reduction of area.

These mechanical material properties characterize the material behavior of metals in terms of strength and ductility. In addition, determining the temperature dependence of metals in their many different applications is of important significance. To investigate this dependence between metals and elevated temperature, various tensile tests must be performed at different hot temperature levels.

ASTM E21: Testing machine requirements

ASTM E21 requires optimal and precise testing machine alignment when applying the load on the gripped specimen. The testing machine and specimen grips must load a precisely machined specimen in such a way that the maximum bending strain does not exceed 10% of the axial strain. It should be noted that the verification of these conditions under elevated temperature is not possible in practice and can therefore be performed at room temperature.