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Elgin Grade 387 Pocket Watch Identification & Technical Specs
Guild Home > Archive > Elgin Grade 387 Pocket Watch Identification & Technical Specs

Serial Number & Production Dating Lookup

Enter the 5 to 8 digit serial number stamped directly on the movement plate (not the watch case):

AMERICAN WATCHMAKER • American Watchmaker Elgin Grade 387 DIAMETER: 42.4 mm | JEWELS: 21 Jewels | FREQ: 18,000 BPH ARCHIVE SPEC
Original Horological Blueprint • American Watchmaker Elgin Grade 387 Movement Architecture

Technical Specifications & Factory Archival Records

Grade / ReferenceGrade 387
Movement Size16s
Jewel Count17 Jewels
Railroad CertificationStandard Grade (Non-Railroad)
Vibrations Per Hour18,000 BPH (2.5 Hz)
Balance Lift Angle52°
Power Reserve37 hours
Escapement TypeStraight line lever escapement
Balance Wheel ConstructionExpansion balance
Hairspring SpecificationBlued steel Breguet spring
Shock Protection SystemRigid balance jewels

Horological Architecture & Collector Notes

The American Grade 387 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 17 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.

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