Screw-on case back opener with 6 interchangeable dies (18.5mm–36.5mm) for Rolex Oyster-style and other waterproof screw-down backs.
⭐ At a glance
📏 Die sizes: 36.5mm, 29.5mm, 28.3mm, 26.5mm, 22.5mm, 20.2mm, 18.5mm
✅ Fits Rolex Oyster-style screw-on case backs and other waterproof screw-down case backs with matching notch spacing
📦 Includes opener tool plus 6 dies (7 pieces total)
✔️ Condition: New with tags
🔧 What it does & how to use
This tool unscrews and re-tightens screw-on waterproof watch case backs so you can access the movement for battery changes, servicing or repairs. It suits both hobbyist watch tinkerers and professional watchmakers, and the set of 6 dies covers a wide range of case back sizes.
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Measure first: check the notch spacing on the case back against the 7 die sizes to find the correct match.
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Fit the die: select the matching die and fit it into the opener head.
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Locate the die: seat the die's pins/teeth into the slots on the case back.
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Secure the watch: hold the watch steady, ideally in a case holder or cushion, so it doesn't twist.
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Turn to open: apply firm, even downward pressure and turn anticlockwise to loosen and remove the back.
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Turn to close: reverse the action, turning clockwise, to re-tighten the back once work is complete.
⚠️ Please check the notch pattern and size of your case back against the 7 die sizes listed before buying — not all screw-on backs use the Rolex Oyster notch layout, and an incorrect die fit can slip and mark the case.
