Impact toughness essentially measures a material's ability to resist fracture or failure when subjected to sudden impact load or shock load. Impact toughness is an important property of materials because it is a measure of a material's durability or resistance to crack propagation under high strain rate loading conditions.

Key Features:

• Measures energy absorption: It measures how much energy a material absorbs prior to fracturing when subject to a sudden impact load.
• Temperature Dependent: A material may have high or low impact toughness depending on the temperature of the impact test (especially if close to the ductile-to-brittle transition).
• Tested According to Standard Procedures: It is commonly measured according to Charpy and Izod standard impact tests, where a notched sample is ruptured by a swinging pendulum.

Impact toughness is important for industry sectors where loading conditions include unpredictable forces or collisions, such as the automotive, aerospace, pressure vessel, pipeline, and structural engineering industries. For example, in low temperatures, a steel that has low impact toughness could potentially be brittle and could fail catastrophically if subjected to significant impact loads. Properly selecting materials with adequate impact resistance helps to avoid sudden failure, improve safety, and increase overall reliability under dynamic load conditions.