Toughness is how much energy something can take without breaking, e.g. the more weight you can put on a tabletop before it breaks in half, the tougher it is. Th

Toughness is how much energy something can take without breaking, e.g. the more weight you can put on a tabletop before it breaks in half, the tougher it is. The opposite of tough is brittle, if that makes more sense. Hardness is how much energy something can take without deforming, e.g. playdoh is not hard.