Toughening is a heat treatment process designed to improve the ability of steel components to absorb impact energy and resist cracking or brittle failure under service conditions. The process typically involves controlled hardening followed by tempering to achieve the desired balance between hardness, strength and ductility. Unlike treatments focused mainly on maximum surface hardness, toughening emphasizes overall mechanical reliability and resistance to shock loading.

Toughened components are widely used in applications subjected to dynamic forces, cyclic loading and heavy mechanical stresses. The process helps extend component life by improving resistance to fracture while maintaining sufficient strength for demanding industrial environments.