Posted June 16, 2014 by Esslinger Staff
Over time your watch stem can wear out or break. Or, often after you decide to replace your watch crown, you may need a new stem to match the tap of the crown. Don’t let your old or broken stem keep you from wearing your watch; you can replace your watch stem yourself with this guide.
Be aware, replacing a watch crown involves a lot of precision since the new crown and stem must fit the watch case perfectly. If at any point you are concerned that this repair is more than you are comfortable dealing with please take your watch to a professional.
- A pin vise
- An end cutter
- A fine jeweler’s metal file
- A digital gauge
- A parts tray
- A watch stem
- A watch crown
- An optional flathead watchmaker’s screwdriver
- And a fine tipped marking pen
The first thing you will need to do to replace your watch stem is remove the old stem if it hasn’t broken or fallen off already.
For help learning how to remove your watch stem, check out either of these links:
Once you have removed the old stem, you’ll need to get a stem to replace the old one. In order to get the correct replacement stem, you’ll need to identify your quartz movement number and use that to order the right size stem HERE.
Use this guide to help you find your movement number:
With your new stem in hand, you are ready to begin. Start by placing your stem in a pin vise to keep it steady while you work. Open the pin vise’s jaws wide and then insert the stem with the threaded side facing out.
Tighten the jaws of the pin vise around the watch stem, closing so that about half of the threaded end of the stem is sticking out of the vise. Be sure that the pin vise is securely closed around the stem.
Then, you will need to fit your watch crown to the stem. Take your watch crown and thread it onto the end of the stem, turning it clockwise. You should be able to easily turn it into place if it is the right size. Know that it will take three to four turns to fit the stem completely.
If the crown is too big for the stem, it will just slip on and off the end of the stem. And, if the crown is too small for the stem, it will not gain traction or thread on to the stem at all.
Use this guide to learn how to measure a watch crown to get the right size replacement crown:
After you have a crown that fits your watch stem, you must fit the crown and stem to the watch movement and case. Remove the stem and crown from the pin vise by loosening the jaws of the pin vise until they open.
Take your watch case and make sure that the watch movement and movement ring are lined up in the case so that the holes for the watch stem are aligned together.
Then, insert your stem and crown into the watch movement, pushing them as far into place as possible and check the fit:
If the watch stem is the right size, the stem will push all the way into the movement and latch while the crown lays flush against the watch case. You can check that the stem fits by turning the watch case over and testing the hands to see if they will move as you turn the watch crown. Check out this guide on replacing a watch crown to learn how to permanently attach the crown and finish this repair.
If the watch stem is too short it will look exactly like it does when the crown and stem fit, except that when you try turning the crown the watch hands will not respond to it. Be aware, that this does not happen very frequently unless you have a pocket watch or a big bling watch. If your stem is too short in these situations you can check out this guide to learn how to insert a stem extender.
Finally, if the watch stem is too long, you will see that the watch crown very obviously does not sit flush against the watch case. If your stem is too long, you will need to follow these next steps to learn how to trim your watch stem down to size.
First, you will need to note how far away the crown is from being flush against the watch case. This distance will be needed to trim your watch stem down to size. Take your digital micrometer and measure the distance from the watch crown to the the watch case, like this.
Record this measurement, and remove the watch and crown from the stem.
Now, you will take that length you just measured and use it to mark off how much you need to cut from the stem. Position one end of the digital gauge’s jaws at the top of the threaded end of the watch stem. Then mark where the second jaw stops on the watch stem to tell you approximately how much stem you need to remove.
Once you have made your marks, remove your watch stem and crown from the movement and replace them securely in the pin vise again. Be sure to position the stem in the pin vise so that both marks are sticking out of the vise.
Remove the crown from the watch stem by turning it counter-clockwise and place it in your parts tray to keep it safe while you work.
After drawing the newest mark on the watch stem, set the digital gauge aside and get ready to cut the stem. Take your end cutters and position them above the mark you just made. Remember: You can’t make a stem longer again, so do not cut directly on the new mark. Instead, leave a little space above that mark.
When you are confident that you still have some room for error on your stem, squeeze the jaws of the end cutter closed and cut off the end of the watch stem.
Set the end cutters aside and holding your pin vise and stem in your non-dominant hand, use your metal jeweler’s file to file around the edge of the cut end of the stem to maintain an even edge that will thread onto the watch crown.
Hold the file against the edge of the stem and then angle it about forty-five degrees so you can bevel the edge and remove any metal pinching up from cutting the tip off. The goal here is to allow the threads to gain traction in the watch crown, not to take off more length.
Once you have filed all the way around the edge of the stem, take your watch crown and thread it back onto the stem. If you cannot thread the crown back into place, file the new end of the stem a little more and then try again.
When you can’t turn the watch crown any more and it is securely on the watch stem.
Remove the watch crown and stem from the pin vise and fit them to the watch case again, like you did before.
Check the fit of the watch crown and the stem. If you are lucky, the crown and stem will fit flush against the watch case and when you test to see if the hands and crown will turn together they will.
Most likely however, the stem will still be a little bit big for your watch.
Remove your watch stem from the watch case and replace it in your pin vise. Then, remove the watch crown and set it aside in the parts tray.
From now until the watch stem and crown fit the watch case you will follow the upcoming method, taking just a small amount off of the stem at a time to avoid accidentally cutting the stem too short.
Take your end cutter and cut off one stem threading worth of length from your watch stem.
Use your jeweler’s file like you did before to smooth the edges of the stem and make it easier for you to thread the crown into place.
Once you have filed all the edges of the stem, re thread the crown back onto the stem. If the crown won’t thread on, file the end of the stem a little more and then try again.
When the crown is completely screwed into place, remove the stem from the pin vise and try it out again in the watch case to check the fit.
Repeat this process, cutting a little from the stem, filing the end and the replacing the crown to check the fit until the stem and crown fit the watch case perfectly.
When you are sure that the watch stem and crown are the right fit for your watch case and movement, you will remove them one last time to permanently attach and seal the crown to the stem.
For help doing this, check out this guide from Step four to Step seven:
Now that the crown and stem are sealed together, you will take your stem and insert it gently but firmly back into the movement and watch case for the last time.
If the watch stem is held in place with a small screw, once the stem is all the way into the movement, tighten the screw back into place with your flathead screwdriver, turning it clockwise until it cannot be turned any further.
With the watch crown and stem now securely attached to the watch case, you are done! All you need to do is close the watch case and go back to wearing your watch again.
Visit Esslinger.com’s Learning Center for more watch repair guides.