Omega Caliber 620

Manufacturer	Omega
Caliber Number	620
Movement Type	Mechanical, manual wind
Linges	7.75”’
Diameter	17.5mm
Thickness	2.5mm
Jewels	17
Beats Per Hour	19,800 vph
Lift Angle	48 degrees
Power Reserve	~42 hours
Shock Protection	Incabloc
Regulator	Fine rate adjustment
Functions	Central hours, central minutes
Hacking Seconds?	No
Country of Manufacture	Switzerland, Swiss made
Known Models	Omega DeVille D 6672 (Add your watch to the comments below…)

The Omega caliber 620 is a vintage 17 jewels hand-wound mechanical movement, Swiss made and unadjusted. This caliber is a 2-hander with hours and minutes only. It is found in vintage Omega dress watches such as the ultra thin DeVille D6672. The 620 was introduced in 1960 and was produced from the 1960s into the early 70s. Omega refers to this movement as “Superflat” as it is only 2.5mm thin.

Omega 620 VS 625:

There is a similar Omega caliber 625. The main difference between these two movements is that the 620 shown on this page beats at a slower rate of 19,800 VPH compared to the 625 beating at 21,600.

Omega 620 VS 630:

As mentioned above, the 620 is a 2 hand movement displaying only the hours and minutes, however, there is a similar caliber 630 which adds a sweeping second hand. Similarly to above, the 630 beats at 19,800 VPH, but there is a 635 which includes the sweeping second hand and beats at a higher 21,600.

“1” Inside Omega Logo:

You may have noticed that there is a tiny number 1 (one) etched inside the Omega logo above the caliber number. This number indicates hand height. 1 for flatter crystals, 2 for slightly domed crystals, and 3 for domed crystals H1, H2, H3 – similar to ETA. This system assists the watchmaker in ordering the correct parts for the timepiece being serviced.

For more information, Omega Constellation Collectors wrote an extensive research essay on this topic which can be read here (pdf).

OXG Stamp:

The balance bridge on this movement is stamped with OXG. This is an import mark that was registered to Norman Morris Imports. This stamp was used from circa 1937 until 1970 when the stamp was no longer required. This indicates that this movement was produced outside of USA and was imported.

Additional Images:

Additional Resources:

• More Omega watch calibers