Bergeon 5338-1 F

This is due to my experience the ideal opener for Polygonal Case Backs with 6, 8, 10, 12 or 14 edges. Very popular are octagonal watch cases as you might know from your browsing of the flea markets.


The 5338-1F with the typical Bergeon box and the text in 4 languages


The 4 bits side with bits 5338-A for polygonal watch case backs


The bit pairs are adjustable for wider angles (10, 12, 14 edge case backs) and smaller angles (hexagonal and octagonal case backs).


A Double Rhomb case back with a 14 edge polygonal case back

Notes about the use of the Bergeon 5338-1 F (4 bits side, 5338-A)

  1. Adjust the the bit pairs to firmly sit on two opposite corners of the polygonal watch case.

  2. Tighten the wrench

  3. Hold the watch in your left palm or on the movement pad first and try to turn counter clock-wise.

  4. If the case back sits too tight, you will have to fix the watch case with the watch case holder.

  5. Once the watch case is securely fixed, try to turn the case opener counter clock-wise

All pictures above refer to the 4 bits side.

Many different sets of this tool available

The 5338 openers comes in a variety of sets. Also a wooden box is available (5338-1E). There is also a variety of chucks or bits available for different case backs. My set 5338-1 F included 4 bits 5338-A for polygonal watch cases and two bits 5338-B for cases with slots. Below is the picture of the side with the 5338-B bits for cases with slots


The 2 bits side with bits 5338-B for case backs with slots

Notes about the use of the Bergeon 5338-1 F (2 bits side, 5338-B)

  1. Adjust the the 5338-B bits (picture above) to fit two opposite slots

  2. Tighten the wrench

  3. Hold the watch in your left palm or on the movement pad first and try to turn counter clock-wise.

  4. If the case back sits too tight, you will have to fix the watch case with the watch case holder.

  5. Once the watch case is securely fixed, try to turn the case opener counter clock-wise

The SANDOZ Submariner-like back is a watch case back the Bergeon 5338-1 F (two bit side) can be used for, but I prefer the JAXA opener using 3 bits for cases with slots. Why? Because if you have 2 bits only, you will have to press the opener perpendicularly onto the watch case. The opener is only supported by two bits and you could easily tilt the opener when applying momentum and slip off.