Curling (metalworking)

[1] Other parts are curled to perform their primary function, such as door hinges.

This will help prolong the life of the die by avoiding unnecessary damage due to scratching.

Curling is often performed as part of a high production, multiple operation progressive forming.

Dies are generally made of hardened tool steel because of the amount of wear caused by the operation.

[citation needed] Their smooth, rounded cavities are often lapped and polished to help curl the material uniformly.