Board Thread:Warhammer 40k General Discussion/@comment-24037808-20150120110001/@comment-25177957-20150121192516

@Attank I hope you are aware that the original Men of Iron were tainted by Chaos and made to rebel against Mankind by the will Chaos Gods.

Tyranids can of course benefit in some ways from metal, and it can probably be reused in some parts on their starships, or to thicken Carnifex carpaces. Necron metal is a whole different thing than the metal other species use.

http://warhammer40k.wikia.com/wiki/Necrodermis