Job Number 210145
Getting ready to cut away the hub of the old staff...
I do the same thing every time a movement like this comes up; spend all afternoon researching the balance staff. Elgin documentation calls for staff part number 861 for many 16 size movements. But there is 861-c, 861 old style and 861 new style. If it needs an 861-c it usually, but not always, says so. If it just says 861 then it could be either new style or old style.
861 new style, or 861-NS, is a bit longer than old style (861-OS) at 5.32mm. Old style is, if I recall correctly, 5.17mm. These two otherwise look the same.
861-C has an oil groove. And it is also longer at 5.32mm. However the hub is a different size. It is not usually a replacement for 861-NS. It seems like I have seen them interchanged, but I could be wrong.
I found I have just one 861-NS staff on hand anymore, and it may be an after market part. It will need a little shaping of the pivots at any rate.
See the album for this project here:
https://photos.app.goo.gl/oxJSjLX3XU781eQw9
Project link (all the posts):
https://pluspora.com/tags/210145_et
Follow all the projects in detail here:
https://pluspora.com/tags/elgintime
#Elgin #elgintime #210145_et #vintage #pocketwatch #watchrepair #horology