Files for Wood/Metal

[Doug Mason]

For those experts w/files, a simple question: I have read that I should have sepearate files for 1) wood, 2) metal and 3) soft metals. Is this true? I'm not talking about rasps, but, for example, a Hand 2nd cut, etc.

[Bill Houghton]

but it does occur to me that, since it's never really possible to get ALL the swarf off a file, it would make sense to have separate files for metal and wood, so you don't get metal shavings in the wood.