This is a swiss army watch I recently was given by a relative to repair, and I’m certain this is a screwback case but how do I actually remove it? There arent any notches for a watch wrench to remove it, so do I use a rubber ball?
You can try a rubber ball. If that doesn’t work, you need to buy a case back wrench with Rolex-style dies.
Might be able to do it with a rubber ball, depends how tight it’s on there vs how strong a grip the ball can get. Professionally, this would be done with something like https://www.cousinsuk.com/product/rolex-dies-6-with-wrench
Failing that, it’s the same type of back as Rolex, so look up how to open Rolex style case backs for other ideas.
And stupid question, have you checked it’s not a snap on pretending to be a screw on?
I’ll second the rubber ball. If you don’t have a correct die for these sorts of finely toothed caseback fittings, a rubber ball may well work. It can be difficult to get enough grip if the caseback is tight, but it may work.
The next step, if that doesn’t work, is a quick curing epoxy which can be removed cleanly with solvent. There are several makes of this sort of temporary fixturing epoxy. Just bond a handle on, being sure to not get any in the joint between caseback and case, remove the caseback, soak the handle and caseback in epoxy remover, and then tighten the cleaned caseback well with a rubber ball so that it’s no so impossible to remove next time. Always use as little epoxy as needed to help keep it from dripping, and use a quick setting or UV curing epoxy so that it doesn’t have time to run before curing.
If a rubber ball does not provide enough traction, some balled up ducttape (sticky side on the outside) might. I’ve had some success with this method, worst case scenario you’re left with a sticky case back, which can be rubbed off with a bit of alcohol.
Your watch appears to be very similar to the Swiss Army model shown below. Although it looks like a screw-down case back, this is actually a snap-on.
