Hi, I've got a 18 size 17 jewel Bunn that needs a balance staff. Does anybody have the part number? Thanks

Hi Bill,

Do you know if the staff is a Single Roller (SR) or a Double Roller (DR) (Part # 47604, 5.90mm in length- 6th model)? If the staff needed is a SR the serial # of the movement will be needed to help narrow down the staff by the model #.

I have a few of each...

The serial number is 1504233, variety 2 wavy pattern movement.

Grade: Bunn

Movement Serial Number:1504233
Grade:Bunn
Model: 6
Estimated Production Year: 1900
Open Face


If you feel comfortable sharing a picture of the balance wheel we might be able to narrow your staff search down a little. The Model 6 came in DR/SR version. Staff # 47604 DR or 47605 SR (small collet) are the most common for the Model 6 from my search. Also, there is # 47632 which is a SR w/ large collet found in some Model 4 and 6.

Good times!!!

Thanks Jon, I'll get a picture up

Sorry it took so long here is the balance

Reminder: 18s open face staff is "short", hunting is "long". Earlier watches used large collet, later were small collet. Example: 18 size open face 17j. grade 69, serial number 1,xxx,xxx would use staff SINGLE ROLLER, SHORT, SMALL COLLET. I suggest tracking down a copy of the C.E Marshall Handy Manual, American section, IMHO the clearest guide to American pocket watch staffs. Learn the movement Models and forget the serial numbers.

Thanks for your advice

The movement is an Open Face model 6 single roller, so the collet is either a Open Face 6886 large or 6890 small collet. That "collet" is a function of the hole size in the cross arm of the balance wheel. I would suggest you remove the staff, measure the collet diameter on the staff and order the part number noting the diameter of the collet.
(fyi, I also marked the 6885 SR staff for Hunting movements. This WILL NOT work on your movement.)

Thanks to all for your help. Another Bunn is now up and running!