anneal

As the hammering hardens the metal it is necessary to anneal it each time after going over the surface.

As the hammering goes on the metal becomes brittle and hard, and then it is passed though the fire to anneal or soften it.

Malleable or wrought iron, if subjected to pressure, becomes brittle, and it is necessary to anneal it.

Throw an asbestos rag over the joint, loosen one pair of the clamps slightly, and leave the joint to anneal.

When the colours are properly burnt in, the fire is suffered to die away, so as to anneal the glass.