Oris Caliber 674 Watch Movement

Brand	Oris
Caliber Number	674
Based On	ETA 7750
Movement Type	Automatic
Jewels	25
Lignes	13 1/4”’
Diameter	30mm
Height	7.9mm
Jewel Count	25
Vibrations Per Hour	28,800 (4 Hz) – early models were 21,600
Lift Angle	49 degrees
Power Reserve	~48 hours
Anti-Shock System	Incabloc
Regulator System	ETACHRON
Chronograph System	Three-plane cam style
Rotor	Ball bearing system
Rotor Direction	Uni-directional
Hacking Seconds?	Yes
Service Interval	~5 years
Features	Central hours; central minutes, central chronograph seconds; small running seconds at 9:00; 30 minute chronograph counter at 12:00; 12 hour chronograph counter at 6:00, date at 3:00
Country of Manufacture	Switzerland, Swiss made
Known Models	Oris Big Crown Chronograph (Ref: 01 674 7567 4064-07 5 21 53)

The Oris caliber 674 is essentially a rebranded ETA/Valjoux caliber 7750 automatic chronograph movement. It features the signature red rotor found on most Oris watches.

Some of the topics covered in this caliber listing:

Calendar Complication:

Technically, the 7750 is engineered to have a day/date, but Oris uses with 674 without the day of the week portion of the calendar complication.

Oris 674 VS 675:

There is a similar caliber 675 which is also based on the ETA 7750. The main difference is that the 674 has a date, whereas the 675 uses the 7750’s full calendar capabilities to display a day/date. As an example, the 675 used in the Oris Big Crown Timer Chronograph features a date window at 4:30, with a day of the week aperture near the center of the dial towards 9:00.

Oris 674 VS 774:

There is also an Oris caliber 774 automatic chronograph movement. The 674 is based on the ETA 7750 and the 774 is based on the Sellita caliber SW500, which itself is a 7750 clone movement. The 774 is found in newer Oris models, following the news of non-Swatch Group brands being cutoff from ETA movement supply.