I have a getty mvt that needs a new mainspring and I need the model # for cross reference.

Mvt # is 1419738, 17J, SW/LS

Thank you
Ed

It should be a model 5 grade 184

Thank you much Mr. Brown.

Your welcome Mr. Kitner.

My cross reference is giving me a 3 digit factory number that does not match any springs I can find.
Anyone have a 4 digit number for a mainspring for the above mentioned watch?
Thanks,
Ed

The book I have shows for a 16s Illinois model 5 the following;

47313 18x6x20.5
47314 18x5x20.5
47315 18x4.5x20.5
47316 18x4x20.5
47317 18x3.5x20.5

I am guessing they must have made barrels of different depths.

I take it you don't have the spring that was in it?

Tom

Tom,
Those numbers in the center are the strength of the spring determined by the thickness.

Ed,
It's usually best if you replace the spring with the same thickness you find in the watch. I have a surplus of NOS Illinois 47317 I'll part with if that's what you need.
RR

Thanks Richard, I guess I need to re-read what the numbers mean again!

I will have to take the spring out again. I am not getting much of a wind on the spring. I was thinking it was set and to weak. With the information you just gave me maybe the wrong one is in it.
Thanks for the help, again.
Ed

I just noticed your post Richard, thanks for the numbers and the offer.

Tom,
Those Dennison numbers are confusing. I like to use the MM scale and it's still difficult. Earlier today I took out a 47317, from a model 9, and replaced it with a 47315. The watch has synthetic oil and the stronger thicker spring was making the balance swing too far, knock, and run fast face down. Also, I haven't been able to find a 47321 which is longer, for the bigger diameter barrel but the short spring will work, just won't run as long.
RR

Tom,
You're right there is a thicker barrel for the model 4 and 5. The brace is different on the thicker barrels.
RR

Thanks Richard

I found a place on the web that says they have the 47321 if you are interested, I think they wany 34.95 for it.

Tom

Ed, You're welcome.
The Thick Barrel is .150 inches and a regular one I just measured is about .141 inches. Typically higher jeweled watches have weaker springs and lower jewel counts require a stronger spring.

Tom,
Thank you for locating the mainspring. I've been trying to limit a mainspring to $15.00 or less. Usually the springs of choice for me are Factory NOS packaged. If the watch the spring was going in was of a higher quality I'd consider spending more on it but it's an average Burlington 21J. Hopefully someday I'll find several of the 47321 offered at once for a lower price.

RR