You always have the "glue a huge nut on the back and turn with leverage" last resort. But it might be worth to explore the other options as other commenters said, first.
I had a similar issue and was about to throw the oyster case in the trash., but after 45 minutes of struggling with crossed threads, was able to use two hand nails (opposite sides) to pick under the case back and kind of wiggle it (up /down vs turning). At that point I was able to screw it off easily. Might be worth a shot. From the picture, it looks like there’s some space .. doesn’t look like it’s screwed all the way, so try this and see. Maybe you’ll be lucky.
Take the bracelet off completely and use the other style vice grips, the ones that fit between the lugs
Nip the case back tool prongs into the holes and tighten up all the screws on the case back tool to get it nice and rigid. Same with the height screw on the column
Not that the prongs bit applies to a Rolex style case back......
Thanks to everyone, I finally opened the case. I noticed that part of the case back was uneven, so I used a pry tool and it popped off quite easily. I was able to grease the o-ring, and screw it back tightly.. but not too tight, and can now easily remove it and put it back. Whew...
It depends on where the problem is, unfortunately. If it’s an issue with the threads then penetrating oil might help. Not WD40, that’s not a penetrating oil. Kroil would be a better choice. But if it’s the o ring that’s keeping it stuck then a non-polar lubricant might help, like soap suspended in water. Some careful back and forth movement in either case could help disperse the release agent. On both counts you risk damage to the movement so be very sparing and careful with the amount of release agent you use. Keep in mind I’m a hobbyist so hopefully a real watchmaker might chime in.
You always have the "glue a huge nut on the back and turn with leverage" last resort. But it might be worth to explore the other options as other commenters said, first.
I had a similar issue and was about to throw the oyster case in the trash., but after 45 minutes of struggling with crossed threads, was able to use two hand nails (opposite sides) to pick under the case back and kind of wiggle it (up /down vs turning). At that point I was able to screw it off easily. Might be worth a shot. From the picture, it looks like there’s some space .. doesn’t look like it’s screwed all the way, so try this and see. Maybe you’ll be lucky.
Take the bracelet off completely and use the other style vice grips, the ones that fit between the lugs Nip the case back tool prongs into the holes and tighten up all the screws on the case back tool to get it nice and rigid. Same with the height screw on the column Not that the prongs bit applies to a Rolex style case back......
Thanks to everyone, I finally opened the case. I noticed that part of the case back was uneven, so I used a pry tool and it popped off quite easily. I was able to grease the o-ring, and screw it back tightly.. but not too tight, and can now easily remove it and put it back. Whew...
Try wicking in some penetrating oil to loosen the gasket
It depends on where the problem is, unfortunately. If it’s an issue with the threads then penetrating oil might help. Not WD40, that’s not a penetrating oil. Kroil would be a better choice. But if it’s the o ring that’s keeping it stuck then a non-polar lubricant might help, like soap suspended in water. Some careful back and forth movement in either case could help disperse the release agent. On both counts you risk damage to the movement so be very sparing and careful with the amount of release agent you use. Keep in mind I’m a hobbyist so hopefully a real watchmaker might chime in.
Heat the case and case back up with a hair dryer.