No matter what blade profile you buy, the blade of the screwdriver must be properly fitted to the slot. This means a snug fit in the slot, and not bottoming out in the slot, as that will lead to cam out.
If the screws have Loctite on them, (likely) then application of heat is the best way to break the bond.
Cheers, Al
I had the same problem with the same bracelet. I bought a 1.6mm screwdriver from Nick Hacko, still couldn't turn the screws, applied heat from a soldering iron and eventually a precision blowtorch all to no avail. So I sent the bracelet to my mate Jiminoz who did this:
20 minutes in an ultrasonic at 80ºC followed by soaking the screw heads in acetone for an hour.
Then another dose of ultrasonic and into the soft jaws and a fitted screwdriver and a bit of "leverage".
Bless him he even got rid of the mess from the blowtorch. This was to fit a Micro adjustable clasp.
How much heat do you need? I tried immersing the bracelet in boiling water for 30 sec, and blasting with a hairdryer for 60 sec to melt the glue / loctite, but I still wasn't able to turn the screws at all using an A & F 1.8 mm screwdriver.
No matter what blade profile you buy, the blade of the screwdriver must be properly fitted to the slot. This means a snug fit in the slot, and not bottoming out in the slot, as that will lead to cam out.Al
Okay, so are you saying a screwdriver should be snug in the slot, but the tip not hit the bottom? How would one manage that with tiny screw? Press the tip into the bottom, and back it out?
And ideally, since the walls of a screw are parallel, should a properly dressed screwdriver be cut to have parallel walls too, as it would seem that a wedge shape would tend to exert more force on the top edge of the screw slot, leading to a greater chance of deformation there.