Hamilton caliber 747 is U.S.A movement from 1940s.
Functions: sub second
Manual-winding movement with 17 jewels.
F = 18000 A/h
Power reserve: N/A
Diameter: 23.2 mm
More information:
Design: Hamilton Grade 747 is a modern three-quarter plate movement with wide bevels on the bridges and the pillar plate. Both bridges and the pillar plate are rhodium plated. The balance cock and both bridges employ integral steady pins. And a case alignment slot in the pillar plate provides for accurate and secure location of the movement in a case. While Grade 747 is the first 8/0 movement Hamilton has ever manufactured in quantity, it is not the first one it has ever designed or made. Hamilton engineers and technicians have been designing and building and studying experimental 8/0 models for more than 10 years. While work on the movement was virtually abandoned during World War II, final development was not sacrificed. The experience and new knowledge acquired building war timepieces proved to be precisely the experience and knowledge needed to complete the project.
Grade 747 is a fine movement through and through. It is a fine looking movement. More than that, it is a fine watch to service or repair. For a quick summary of the outstanding features of Hamilton Grade 747 see the description below.
Size: 8/0 Round
Jewels: 17 – Direct friction set
Winding and Setting: Rugged construction, smooth action; entire stem hole in pillar plate
Minute Wheel: Skeletonized for visibility of third lower jewel
Cannon Pinion: Improved fit to center staff
Click Spring: Extra long to reduce stress
Click: New Design, affords increased recoil protection of mainspring
Setting Cap Spring: Accurately located by steady pins in pillar plate
Mainspring: Extra long for improved performance
Train: Completely new; maximum freedom. smoothness, and efficiency of operation
Escapement: Completely new; lever type; highly responsive
Balance: Mono-metallic; 18,000 oscillations per hour
Balance Cap, Upper: Camlock construction for accurate alignment; no screws employed
Balance Cap, Lower: Steel, nickel-plated; two screw type; screws thread into cap from train side of pillar plate
Hairspring: Hamilton Elinvar-Extra; overcoiled
Hairspring Stud: Round, V-seated for accurate and convenient locating
Hairspring Stud Screw: Long head with deep slot
Regulator: Smooth, positive action
Screws: Employ new series of thread standards; balance screws designed with a “dog” point instead of cone point
Interchangeability: Complete except for hairspring which requires matching with balance wheel
Service Convenience: Maximum accessibility for all service and repair operations
Looking for more info? ? Hamilton caliber 747 watch parts
