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Cross ref Bulova movement # to the original manufacturer

Hi folks;
I am new to this site.

Have discovered through another forum that Bulova's 7AK movement is at its heart an ETA 735.

In looking at the whole 7 series they all look ETAish.

So how many of Bulova's movements were based on brought in ebauches?

Given that they had a factory in Switzerland was it common practise for them to bring in movements and then finish them up ; send them to the USA; and then case and time them there.

Knowing how often this occurred would be helpful in sourcing parts.

I have taken the dial off a couple of 7AK's and they are stamped with the ETA mark.

Ahy info would be helpful.
Best regards

Reverend Rob's picture
Reverend Rob
Panel Member
Posted November 15, 2017 - 10:16am

Bulova sourced ebauches from many makers. They also did in-house Swiss movts almost from the beginning. Bulova often would modify the ebauches, so despite being made by ETA or FHF or AS, the balances were usually quite different and not all parts are interchangeable. 

The 7''' series runs the gamut from Peseux to ETA to A.Schild to Aurore Villeret to Felsa to Michel. 

Bulova sourced ebauches from:






















I should also mention that Bulova manufactured movts entirely in the US, and that these are in house and Bulova designed from start to finish. This also occurred in the early days when Bulova's Swiss factories turned out Bulova designs for Bulova. It should also be noted that what Bulova was doing in using ebauche suppliers was no different than what the vast majority of watch companies were doing at the time, or had done at some point in their history. You would be hard pressed to name a company that never sourced movts although Seiko satisfies that description. Even Patek and LeCoultre used ebauches, (Limited use) and Rolex used many over the years. 



Ben Knebel
Posted November 15, 2017 - 6:31am

Thankyou for the info---much appreciated.

Where did you get your info from?
If you don't mind my asking?

Is there a reference book I should get?

Reverend Rob's picture
Reverend Rob
Panel Member
Posted November 15, 2017 - 10:28am


Interchangeability lists are nothing new in the trade, and as you have mentioned, are critical in determining feasibility of repair for watchmakers. Probably the best known reference books are the Bestfit watch materiel 'Encyclopedia' volumes I and II. 

These are available in used condition online, but it is still possible to get them From Besfit if you open an account. 

Another excellent resource is Dr. Ranfft's Pink Pages for Timepieces:


Ben Knebel
Posted November 15, 2017 - 1:41pm

Thank you all very much for the information.

I discovered the pink pages this morning and
Was about to post the link

You beat me to it Reverend Bob.

I didn't ask the question to disparage Bolova in any way as I am well aware that sourcing parts and/or complete movements from other suppliers has been common practise in the watch industry for hundreds of years.

I've been collecting for a lot of years so I run into this a lot; although it does seem to be a little more widespread in wristwatches than in pocket watches or clocks, particularly the vast number of different suppliers used by any one company.

Once again thank you all.

Ben Knebel
Posted November 15, 2017 - 2:29pm

Sorry folks I guess I hit save a few too many times.

Geoff Baker
Club 5000Panel Member
Posted November 16, 2017 - 6:27am

Not to worry Ben, just like a fine old Bulova we can usually fix things up!