How to Size Any Watch Mainspring to a Barrel

In this video, I'll be discussing how to size an incorrect watch mainspring. If you're new to watch repair or watch troubleshooting this video can save you a lot of aggravation, you know how important it is to keep your watch running smoothly. A mainspring is a crucial component of a watch movement that provides the power necessary to keep the watch running and if it is sized incorrectly for the watch's correct condition, you will have problems with amplitude and regulating the watch.

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[ptchan]

There is a reason why I signed up for your watchmaker course. You produce content others just gloss over. Thanks Alex.

[WatchWithMike]

Here's why this video is awesome: I purchased a mainspring from a company that listed replacement springs 'by brand + movement number'. The spring I received was the wrong size. I re-watched this video and had the confidence to size the correct replacement mainspring, based on the barrel dimensions. (It's much different than what they sent!) Knowledge is power - thank you, Alex, for sharing the knowledge!

[chuckfinley]

I can’t tell you the number of times I’ve acquired vintage watches that have come with entirely wrong mainsprings. In my rookie days, I would dutifully order a replacement mainspring by measuring the width, thickness & length of the old spring, punch in the numbers at CousinsUK and then wonder why the watch still ran poorly. I learned more from my mistakes than my successes.

[johnleonard]

Great content again. Your confidence building closing statement " ... is going to make you a better watchmaker", will be remembered as a "classic" someday.

[HeliBenj]

Short, to the point and packed with nuggets of information. Again. Glad to see your channel is slowly but surely picking up steam, well deserved for all you bring to this great hobby. The joy of getting knowledge that I can apply and gradually getting better is invaluable, thank you so much Alex

[TropicalSpeed]

This is very good stuff.
It answers allot of questions that I had hanging but didn't quite know how to ask.

FYi: I replaced the mainspring in a Waltham 620 that has an amplitude problem. I ordered a new, generic, Swiss mainspring after measuring the 620's mainspring and concluded that it did not fill those barrel minimums mentioned in the video.
Also, I was able to order the correct size mainspring after watching the video and got it right the first time.
Now the the amplitude is good.

[hisstorymn]

Sir you are an inspiration for us amateurs! Thank you for your instruction.

[stevefeeney]

I just ran to my notebook to write down that formula. Thank you again Alex. 😊

[tomholloway]

Thanks again Alex, informative as always. Good to see the channel growing so well too.

[paulofdirt]

Subed a week ago and learned more in that time then a year on any other YouTube channel. Finally one for the little guy.

[BradMeehan]

Not only is the content great, but your video production is really evolving with every video.

[roadshowautosports]

You got my subscribe at the “ID of the barrel divided by 87”
I’m an apprentice without a master and it was super helpful to know these little details on the how to get to a better result.
Thank you!

[Qwertz]

Thanks a lot for all the knowledge! Great videos! How to spec main spring video…. Important, easy to Unterstand, easy to apply 👍

[MrTerrierLove]

This is was a gem of a video to find! I've just taken apart and cleaned 2 Elgin and Omega pocketwatches and am about to order the new springs. I am a novice but have replaced a few. Your superb method and brilliantly explained video is a revelation after some of the shenanigans I've employed to get measurements 😁

[treetopspider]

Your lessons here are so good. Ive almost watched them all. You make everything so simple to understand.
Thank you for all your good work

[mikebruegger]

Very important indeed to have the knowledge on how to figure out a comparable spring to the original for vintage movements.

[MichaelB-qxeh]

This is so great, thank you. I'm struggling right now with a UTC movement that is knocking, hits 360deg even at a very low wind and I've been gathering info to replace the spring appropriately. This is so timely, I really appreciate it.

[rossjackson]

Thank you Alex. Once again you seem to have pre-empted the learning scale of us beginners. Learning for me is two fold. Gain knowledge, which is by progression from one level to the next, understanding that level to allow the progression. I have great difficulty understanding the written word to assimilate. Show me, talk to me and I will remember and understand a great deal. Each video is an increase in the depth. Again. Thank you

[steinskotmyr]

I simply love your tutorials and explanations. It’s not difficult to understand that you have an ocean of experience and knowledge under the belt. I have learned a lot watching your videos with great satisfaction.

[yizhang]

I've watch many of your videos, they are high quality, informative. They brought me into the watchmaking hobby! And this hobby made me so happy on many weekends! Thank you so much for distributing the knowledge and fun!!!