So "drag knife" is not the correct term. The correct term is "tangential knife".
This is only relevant because it is how engraving works.
"Engraving" in watchmaking is a barely-automated process called "engine turning" everywhere but the US, where "engine turning" means something else entirely because of course it does. The first lathes in europe were actually for "ornamental turning" and it was very much the sport of kings.
When applied to jewelry, this is called guilloche, a made-up word much like "karaoke" or "boba" that is foreign but with an extremely muddy etymology. So muddy in fact that half the world (and it is an exceedingly small portion of the world) says "gee-oh-shay" and the other half says "gwee-osh."
Guilloche sucks. I've done about 30 hours training on it. I hate it.
Note that I also hate the wire-bendiness of cloisonne, but love the paint-by-numbers of it. Solution? mechanize that shit.
This is a Bumotec S191V. It's yours for a mere $750k.
But it can be tricked into doing mayhem.
And, for roughly $25k out the door, so will the FrankenKern.