Unitas Caliber 431

The Unitas caliber 431 is a large handwound mechanical pocket watch movement. This calibre is considered to be a larger version of the popular ETA/Unitas 6497. Circa 1940s ~ 1960s (unconfirmed).

431 VS 6497:

*Check back soon for side-by-side images.

You may be wondering if the 431 is more closely related to the 6497 or 6498, since the small seconds hand is at 6:00. Keep in mind, that this is a pocket watch movement, and the seconds hand is at 6:00 with the crown at 12:00 (lepine style). If this movement is in a hunter style pocket watch case (with the crown at 3:00), the everything rotates clockwise 45 degrees to place the small seconds at 9:00 – hence the comparison to the 6497.

Learn More: ETA/Unitas 6497 VS 6498 Differences

Macro Gallery:

Watches with this caliber:

The Unitas 431 example featured in this caliber listing was found in this Waltham pocket watch from the 1960s – possibly during the time in which Waltham Watch Co. was acquired by “a Swiss group headed by the Invicta Watch Co.” (source).

Additional Resources:

• More Unitas watch movements