Pocket Watch Database

Possible Interchangeable Balance Staffs

Illinois #989/47621

The following table contains a list of balance staffs that are very close in measurements to the Illinois 989/47621 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
Illinois 3/0 989/47621 3.92 0.92 0.65 0.55 0.44 9-9.5 Buy Now
Hampden 3/0 9720 3.95 1 0.66 0.57 0.37 Buy Now
Data Source: Swartchild Balance Staff Charts and Company Material Catalogs
Pocket Watch Balance Staff Diagram