I have several screws that need to be removed from a 2x6 piece of wood
that forms the base of my raised stove hearth. I've tried drilling
into them to be able to remove the board, but my bits won't cut into
the metal and my bit is dulled. What type of bit would penetrate into
the screw? I need to remove the boards so I can lay a Pergo-type floor
underneath them, trim the boards, re-paint and replace the boards
around the hearth.

Greg