Enter the 5 to 8 digit serial number stamped directly on the movement plate (not the watch case):
Original Horological Blueprint • American Watchmaker Elgin Grade 291 Movement Architecture
Technical Specifications & Factory Archival Records
Grade / Reference
Grade 291
Movement Size
16s
Jewel Count
7 Jewels
Railroad Certification
Standard Grade (Non-Railroad)
Vibrations Per Hour
18,000 BPH (2.5 Hz)
Balance Lift Angle
50°
Power Reserve
36 hours
Escapement Type
Straight line lever escapement
Balance Wheel Construction
Bimetallic compensation balance with gold screws
Hairspring Specification
Breguet overcoil hairspring
Shock Protection System
Rigid balance jewels
Horological Architecture & Collector Notes
The American Grade 291 was engineered to meet rigorous American horological standards during the turn of the 20th century. Utilizing high-grade alloy components, a precision Straight line lever escapement, and 7 jewels with fine ruby endstones, this movement provided exceptional isochronism and positional stability.
Among vintage restorers and conversion specialists, this series is admired for its accessible gear train geometry and solid metallurgy, making surviving specimens excellent candidates for preservation and custom recasing. For examples of restored and converted specimens, see AntiqueWrist Atelier.