radius becomes infinite () and . In this case, the formulas yield the same result as because changes according to the ratio .

The parameters () obtained from a test result can be used with these formulas to calculate the equivalent true stress at failure. The graph of specimen shape effect shows how the ratio of true stress to engineering stress (?´/?_e) varies with the aspect ratio of the test specimen (). The curves were calculated using the formulas provided above, based on the specific values presented in the table