Crown & Stem Replacement
Replacing the button and stem is a regular job you will encounter especially at the daylight saving time changes. There are a few common reasons why crowns and stems break these include:
- Rusty stem. If the stem is so rusty that it has broken then probably there will be problems with the watch as well.
- Hamfisted people who do not realise how delicate watches are
- Being caught knocked or bashed
- Crowns unscrewing from the stem. Usually caused by either rust stopping the stem moving or a badly made crown and stem.
- Faulty bolt. Possibly caused by hamfisted people, or being caught.
- Just worn out with age
there are 5 types of crown that are common on watches
- Standard Water Resistant: these are found on the majority of watches. Note: Black seal Stops water ingress
- Screw Type: Now much more common than they used to be. these are great for water if the customer knows how to work them. Note: Flat black seal Stops water ingress.
- Dust Proof. Now common on battery watches which this guide is aimed at but you will find them on watches which have been converted to quartz from mechanical. Note: No Seal but spring pushes ring onto watch casing stopping dust ingress
- Japanese. Found originally on Japanese watches but becoming more common. Note: Black seal Stops water ingress
- Basic (Cr*p). These have no seal and are not worth keeping in stock. If you can’t keep water and moisture out of a watch you can not be sure that it will be reliable.
the steps for making a replacement crown and stem is the same for each type although there are a few things to bare in mind for each
- Remove winder and Crown
- Clean case around pendent
- Check pendent is OK. It must be smooth and cylindrical so the seal can do its job and must be fixed in the casing well. If not Change it if it is not round or is badly marked or re-glue it is it is loose.
- Find the closest replacement to the original crown if Crown needs replacing. The most important measurement is the pendent size. this must fit otherwise
- Find replacement stem.
- Cut stem to approximate length and file damaged thread. Fit crown and test in watch. Repeat this until winder is perfect. It should enter run position fully after pulling it out to time set position with no gap between crown and case.
- When its perfect remove stem. Remove crown and dip the end of the tread in loctight or super glue and refit crown. If you leave the stem too long you could have problems. See here
- Remove excess glue
- fit to watch and test how the winder is functioning
- if OK then fit watch back and retest
Obviously you do not always need to replace both the crown and stem but the process is identical. The most important thing is that the crown fits the pendent to stop water getting in.
Tip: If you need to re-use the button when the stem is very rusty have a look at how i go about it
If you have a screw crown that has come apart then sometimes you can repair them with these instructions