Case Back Removal Tools - The Essential Basic Tools of Watchmaking
Updated: Aug 11, 2020
So before you can even see (unless the watch has a display case back) and work on a watch movement you need to remove the case back.
There are 4 main styles of watch case back that you should be aware of as follows:
Snap Off Case Back
Notched Screw Case Back
Screw Off Case Back
Case Back with Screws
The Snap Off Case Back and the Notched Screw Case Back are the most common I've come across so far.
1. Snap Off Case Back
Mostly used in older vintage watches but also some modern watches, this is simply a case back that is snapped on or off in one motion.
To open a snap off case back you simply wedge a knife (preferably pen-knife) or case opener up against the edge of the case back and flip the tool upwards to force the case back to un-snap itself and become free of the watch case. Some case backs have a small lip/notch (as can be seen in the photo to the right in the bottom right hand corner of the case back) used to wedge your tool of choice to make this process easier.
There is a small risk of damaging or scratching the case with this method so proceed with caution and be careful not to cut yourself in the process.
There are a few key tools to aid in this process:
A standard pen knife is a great tool for this purpose and is what I was taught to use, but it is a personal choice. A pen knife also has the dual benefit of being used to sharpen your pegwood (which we will come to in future posts). I was taught to go for a carbon steel blade as this is gentler
and slightly more forgiving on the case metal in-case of scratches.
Basic Variety = around £8
Go for a cheap option with a carbon steel blade.
Case Back Opener Tool/Knife
The more standard case back opener tool comes in these two guises. I've not used these myself as I've always managed with my pen knife but they are good alternative options.
Basic Variety = around £3
Go for a cheap option.
There are other tools available, a few being much more industrial but I've not needed them so far.
Snapping the case back back on once you're done is a fairly easy process and doesn't require any tools. You just need to line up the case back, making sure if there is a notch in the case back (most likely for the stem) that this is lined up correctly before you apply any force with your thumb and fingers. A squeeze will generally suffice and you should hear the re-assuring sound of the click as it snaps back on. Inspect the case back edge all around to make sure it is on evenly to the case.
2. Notched Screw Case Back
This is definitely the most common case back type I have come across and also the easiest to remove and reattach in my experience.
The big give away in these types of case back is the notches around the edge of the case back, normally 6. Be wary, I have come across many vintage watches with a notched case back that are actually snap off case backs in disguise. Would love to understand the rationale behind this but doubt I ever will.
If you find a watched with what looks like a notched screw case back that is stubborn as hell and won't budge with the tools suggested below, then I suggest you try one of the snap off case back tools instead, just on the off chance.
There are a few tools available to assist for this purpose, i'm going to cover the two most common.
2/3 Prong Screw Case Back Opener
These are designed to have adjustable and interchangeable prongs so you can adjust the prong shape (size and thickness) and width apart so they fit snugly into the notches on the case back perfectly and then give you the grip you need to turn and tool which will unscrew the case back.
There are also 3 prong variations (called Jaxa type) which are more stable and reduce the risk of the prongs slipping out of the notches and scratching the case back.
Basic Variety = around £3-7
Branded Variety = £85-150
It's worth splashing the cash for the 3 prong Bergeon Maxi Jaxa tool to minimise any risk of damage to your case back.
I've not used either of these types of tool as I've always managed with the next tool which is also one of my favourites.
Sticky Friction Ball
Originally I bought the blue sticky friction ball (at the top of the photo) very cheaply via eBay but on arrival realised it came deflated and without the valve adaptor to allow me to easily inflate it. This and the lack of a pump made me decide to go for a branded option and pay more for a Bergeon Sticky Friction Ball. You'll hear a lot more about Bergeon from me as time goes by, but basically they are the biggest Swiss manufacturer of quality watch tools but equally are one of the most expensive.
This is one of the simplest and most useful tools you will buy, you simply put your watch face down on a watch cushion, case holder or hold it in the palm of your hand and then push the ball onto the case back and turn, the friction of the rubber grips the case back and unscrews it and the best thing is there is no risk of scratching the watch case.
To close a notched screw case back, you first manually screw the case back on (making sure it's not crooked or slanted against the case) and then use the above tool of choice tighten it as much as possible.
Basic Variety = around £2
Branded Variety = around £9
It's worth splashing the cash for a branded sticky friction ball from Bergeon or Horotec that will arrive inflated and ready to be used.
3. Screw Off Case Back
The screw off case back is identified by a series of edges, grooves, or threads (like the edge of a coin) around the outside edge.
I've not come across any of these types of case back as yet, but they are quite common on Rolex and Tudor watches, but I have a lot more to learn before i'd consider taking one of them apart!
Normally you would use a special tool to remove these. These tools come with multiple size bezels so you will use the right size bezel for the case back, snap on the handle and twist to unscrew the case back.
Again i'd recommend you use a watch cushion or case holder for this to minimise any risk of damage to the watch case.
4. Case Back with Screws
The final type of case back is one with screws which is quite common for digital watches especially in Casio watches.
These are easily removed with a set of precision screwdrivers (covered in more depth in this post). Make sure you to use the correct size screwdriver, rule of thumb is that the width of the screwdriver tip should match the width of the screw head, this will mean you have good contact and reduce the risk of a stripped screw which you will struggle to remove.
Always purchase screwdrivers with replaceable blades for longevity.
One thing to be aware of here is that although all watch movement parts only use flat headed screws there may be some case backs that will use Phillips headed screws so you may need both types of screwdriver sets.
Basic Variety = around £6 for a set of 7
Branded Variety = around £12-15 per screwdriver
It's worth splashing the cash for a branded set of precision screwdrivers from Bergeon or Horotec as this is a key tool you will use constantly. I use the Horotec MSA01.218-A screwdriver set pictured above, bought from Eternal Tools, and I've been very happy with them.
Or this Bergeon 30081-P05 Set Of 5 Watchmakers Ergonomic Screwdrivers, also with replaceable blades, for a bigger budget on Amazon.
So that's all I have to say about case back removers for now, I will most definitely add and edit this post as I learn more and am able to source photos of the missing case back types and tools.
If you think I've missed anything or have anything to add, please comment below.