Measuring For Stem Extender

[dbals]

So I bought a Jules Jurgensen diver style watch with a broken stem ~$11 with shipping.  I knew it was in need of a good cleaning-  when I got it in hand, wow- was it dirty (I really mean disgustingly dirty).  The seller mentioned he loved the watch and it hadn't left his wrist in years until it needed a new battery.  He broke the stem while trying to change the battery.  So when I got it- I literally put on gloves because it had at least 1/8" of grim/dead skin, brushed the back clean-ish opened it/removed the movement and dropped the band and case in the heated ultrasonic for an hour.  Looked like a different watch after that- a little polishing to the case/band and lots of buffing to get the scratch marks off the back of the watch.

 

 

The writing on the movement are as follows:   Jules Jurgensen    Swiss Parts USA      Ronda SA.  1 jewel.   I was just gonna buy a new stem but I cannot find the appropriate Ronda movement as this movement has both Day and Date.

 

 

Finally the question:

I see lots of different sized stem extenders, should I just buy the assortment and call it a day or measure and buy the exact one?  Also, do I need to know the pitch or is outside diameter enough to figure it out.  Normally I would do this for normal pitch calculating: By laying a steel rule down the axis of a screw and counting the number of thread crests in a given length, the pitch can be determined by dividing the count into the length.

 

Sorry guys,

Feeling a little lost

 

Dan B.

[bobm12]

Hi Dan,

 

I don't know what a true watchmaker will do, but I will tell you what I do in that situation. There is a gauge I found in esslinger.com (picture) where you can test the stem and determine the tap (i.e. tap 10, 11, etc.) with that you can order the right replacement.

 

Alternatively, you can order the stem and crown from a supplier so they match. I've done that too on occasion.

 

I hope it helps,

 

Robert

 

 

[Geo]

Hi Dan, the diameter is all you should require to get the correct extender!

[dbals]

Thanks guys!

[Lee]

Ronda movements have a number on them but its often faint to see, usually on a plastic part of the movement or down by the battery. if you have this you should be able to order a new stem without problem. if your using a stem extended to repair the old one, then use measuring calipers to get the diameter of the old one, probably 0.9mm. if you want me to add some picture to explain any of that I will!

Edited July 8, 2014 by Lee

[dbals]

Thanks Lee.