I came across this video and though it is pretty cool. Not exactly engraver, but this device allows to leave non-removable lines on any steel. Video is in Russian, but you don't need to hear what he says, it is all clear and obvious. I did not try it myself. Yet... ))
Carbidizing tool. Good call on the rubber glove. Overseas they have 230 Volt mains, not for the faint of heart.
Dan ....would that be more like etching, than engraving? After seeing that ..ill stick to my Dremel...
It's like carbon arc welding. I've mostly seen makers applying tungsten carbide this way to toughen wear point on folders and occasionally the cutting edge of blades. Grimsmo does it with 140 Volts DC.