Reference Library
Possible Interchangeable Balance Staffs
E. Howard Watch Co. (Keystone) #341
The following table contains a list of balance staffs that are very close in measurements to the E. Howard Watch Co. (Keystone) 341 staff and might be interchangeable with slight modification. A factory-sized staff is always recommended and alternatives should only be considered in rare situations where a factory staff is unobtainable.
Please only attempt to fit alternative staffs if you have the skills neccesary to make proper measurements and alterations.
These balance staffs are within a +/-0.1mmm tolerance for each measurement (length, balance seat diameter, hairspring seat diameter, roller seat diameter, and hub diameter) when compared to the source staff. Vertical dimensions and pivot size may differ. Please proceed with caution when attempting to fit an alternative balance staff.
| Manufacturer | Movement Size | Part Number | Length (mm) | Balance Seat (mm) | Hairspring Seat (mm) | Roller Seat (mm) | Hub (mm) | Pivot Sizes | Image | Purchase on eBay |
|---|---|---|---|---|---|---|---|---|---|---|
| E. Howard Watch Co. (Keystone) | 16 | 341 | 5.45 | 1.3 | 0.95 | 0.66 | 0.46 | Buy Now | ||
| Rockford | 16 | 739 | 5.55 | 1.25 | 0.87 | 0.73 | 0.46 | Buy Now |
Data Source: Swartchild Balance Staff Charts and Company Material Catalogs
