Hardenability and Jominy Test

The Jominy End Quench Test, ASTM A 255, is used to measure the hardenability of steels. Hardenability is a measure of a steel’s capacity to be hardened to a certain depth when quenched from its austenitizing temperature. Hardenability should not be confused with hardness, which refers to a steel’s ability to resist deformation when a load is applied. Hardenability, on the other hand, relates to a steel’s ability to be hardened to a specific depth under defined conditions. The information obtained from this test is crucial for selecting the appropriate combination of alloy steel and heat treatment to minimize thermal stresses and distortion while manufacturing components of various sizes.