The Engraver is also referred to as a Surface Marker and can be used on any Metal.
It's a "Hammer" Style Engraver - meaning it oscillates Up and Down very quickly rather than a Rotating Style Engraver that Spins.
The Engraver is incapable of "Digging" in to the Surface of any Material can only achieve a Depth of about 1mm.
You do have some control over the Width of the "Mark" the Engraver makes by adjusting how fast it traces the Design.