Waltham 18s

[Murks]

A got this waltham 18s model 1870 I'm looking for a mainspring to fit the pocket watch does anyone knows where a should look?

[mikepilk]

14 hours ago, Murks said:

A got this waltham 18s model 1870 I'm looking for a mainspring to fit the pocket watch does anyone knows where a should look?

Looking in Swigart and Marshall I can't see an 18S model 1870, only a 14S.

Can you measure the spring ?

Then try Cousins, or https://www.daveswatchparts.com/Mainsprings.html

 

[JohnC]

Look up your serial number on Pocket Watch Database. There should be a link to the model, with a list of parts which should include the mainspring code. You can also take measurements and compare to this page:

https://pocketwatchdatabase.com/reference/mainsprings

which lists most (not all) mainsprings. You can then ask a local supply house which may carry an appropriate spring, or look on eBay. I would avoid old blue steel springs but even old alloys tend to be good. You can also look on CousinsUK, as suggested above, for a generic spring that will fit the movement.

[JohnR725]

Always nice to give us a picture of the watch.

Then for American pocket watches just take the mainspring out measure the dimensions. That would be the width of the spring. The strength which is the thickness followed by the length in inches. Yes inches for the length metric for the other. Then we need the type of end the spring has

Then because you didn't give us a picture and conveniently I didn't memorize every single model number of American pocket watch I'll have to guess that this is a full plate? If this is an 18 size full plate pay attention to how the mainspring barrel and arbor go together and which direction the mainspring goes in. Or basically take lots of pictures. Typically on 18 size of full plate watches the mainspring is left-handed.

They usually it's easiest to find your mainspring if you just measure the size of whatever's in there. Besides even if you look up whatever spring is supposed to be in their bike in the case of this watch it comes in two separate sizes depending upon whether it's key wind or stem wind which you didn't tell us and the thickness can vary because of it just can apparently. So that's why it's always nice to measure the dimensions of the spring in the watch because the books aren't always exact on what is actually supposed to be in their. Then do certain degree it doesn't matter because are going to be limit order of what you can you replace it with anyway. That's because they typically don't make every single mainspring that was ever made for American pocket watches.