This shows up as a blue area on the metal.

I have never tried it on so much metal at once.

So the paper's first seven issues were produced on old, hot metal.

Then his head fell on the hot metal of the tube.

Her short laugh was like a saw on thin metal.

They came off easily and left dark patches on the metal.

It does not usually apply to the attack on other metals.

He took her hand and placed it on the cold metal of the lock.

Someone else had tried this before him: there were fresh marks on the metal.

Bracing her hands and feet on the cold metal she looked out.