Folks,
Can someone please tell me what balance staff I need for a Rockford 16s, 15j, serial #581676, grade 585, model 2, single roller -- what part number do I need? Thanks,
Pete Belmonte

According to my reference the 16s, model 2, single roller would take factory staff #739 and the double roller would be #729.
Might be best if you get someone else`s confirmation on that before you order, however.

Peter,
Here`s a link to the Dashto site`s page on identifying American balance staffs.
I have found it to be very helpful.

Dashto staff page

Thanks very much, Kenny. This is the first Rockford I've worked on. It needs: staff, crystal, minute hand, cleaning, oiling (so far). But, the lady wants it fixed, so I'll give it my best shot.
Pete

...Peter, an invaluable reference to the dimensions of American balance staffs and the factory #s can be obtained from our own Julian Smith for a modest fee...wouldn't be w/o mine...

Thanks Jim, I have now obtained a copy of the list.
Pete

Peter,

We also have American staff information on-site. Go to the Helping Hand tutorials and look for "American Pocket Watch Staff Dimensions". You will need MS Word to view it. The information was obtained from an old Swartchild's supply book. If anyone finds any decrepancies, please provide me with the correction(s) and I will update it.

John,
I just now saw your reply, thanks very much. I obtained a #739 staff from a friend, but it appears smaller than needed -- for example, the roller slips all the way to the hub. So, perhaps the staff was in the wrong or mismarked envelope. I'll have another go next week.
Pete

Peter,

Do you have the critical dimensions from the old staff? Such as overall length (we can allow for broken pivots), hairspring seat, roller seat, hub width and balance seat.

I have one Rockford 739 staff that might work.

John,
Here are the measurements -- making allowance for sloppiness in measuring, I'd say this is a #739.

roller seat: .70mm
balance seat: 1.31mm
hairspring seat: .85mm
hub width: .48mm
length, top of good pivot to broken pivot: 5.33mm

Thanks for any help you can give me,
Pete

Peter,

I measured my 739 staffs and none of them come close to your example. The assortment is an old one and who knows if the right staffs are in the right tubes. The factory 739 had the following dimensions which are all close to yours except for the balance seat which is critical:

Roller - .73
Balance - 1.25
Hairspring - .87
Hub - .46
Length - 5.55

Adding approx .2mm for your single broken pivot would come out about right for the overall length.

Sorry I couldn't help and good luck finding one that will fit!

...Peter, my guess is that your replacement staff is likely a #519 (also intended for a Rockford 16S SR) with a roller seat measure of .62mm...a quick check of it's roller seat dimension will confirm it...in any case Tom Mister @Dashto has #739 Rockford staffs available and I've never received anything but the correct staff from him yet...

John and Jim,
Thanks very much for the input. I'm going to re-measure and then check with my friend (who has more staffs for me to look through) again before I check with Dashto.
Pete