Toughness

Toughness is the ability to withstand shock or absorb energy without fracturing. Hammer handle shafts for example, and many other tool handles, are often made from Ash because it is a particulary Tough timber.

More specifically, Toughness can be regarded as an opposite to Brittleness but weak Ductile materials are also not Tough. Materials which are Tough are both Strong and Ductile.

The Toughness of a material is related to the area under its Stress-Strain Curve and is measured by Impact Testing whereby a weighted pendulum is swung against a test piece to assess the energy needed to break it.