Differential tempering is a method of providing different amounts of temper to different parts of the steel. The method is often used in bladesmithing, for making knives and swords, to provide a very hard edge while softening the spine or center of the blade. This increased the toughness while maintaining a very hard, sharp, impact-resistant edge, helping to prevent breakage. This technique was more often found in Europe, as opposed to the differential hardening techniques more common in Asia, such as in Japanese swordsmithing.