Which part? It's scattered.
I don't think it has a .c file for itself. Last time I checked ( A long time ago ), since it's a very simple element, it is declared with the others, but nothing more.
That doesn't help much. What do you want to do with the metal?
Sparks, metal glow and auto-heating are handled in elementdata.c with PROP_HEATGLOW and similar.
boxmein:
Sparks, metal glow and auto-heating are handled in elementdata.c with PROP_HEATGLOW and similar.
What's auto-heating?