Oris Caliber 645

The Oris caliber 645 is an automatic watch movement with a small seconds subdial at 9:00 and a pointer day hand. This caliber is based on the ETA 2836-2 and was introduced as far back as 1999.

The 645 has the characteristic red rotor that Oris is known for.

ETA 2824-2 or 2836-2 Base?

While older documentation referred to the 645 as being based on the 2824-2, The current Oris catalog references the 2836-2 as the base movement. This makes sense since the cal. 644 (pointer date, small seconds) is based on the 2836-2, and the 2836-2 is the day/date version of the 2824-2 – but it doesn’t answer where the 2824-2 information came from. Was is a mistake on the old marketing materials? Did they change the base to the 2836-2? Caliber Corner will attempt to reach out to Oris for clarification, and will update this page accordingly. In the meantime, we’re going with 2836-2 as the base (based on current Oris specs).

645 VS 644:

Oris calibre 64s watches look like 645 powered watches from a distance, but upon closer inspection, the central pointer hand on the 644 is a pointer date, compared to the 645’s pointer day with date at 3:00.

Additional Resources:

• More Oris calibers