Ulysse Nardin Caliber UN-816

Brand	Ulysse Nardin
Caliber Number	UN-816, UN816
In-House?	No
Base Caliber	Sellita SW300-1
Movement Type	Automatic, self-winding mechanical
Lignes	11.5”’
Diameter	26.5mm
Height	3.6mm
Jewel Count	25
Beat Rate	28,800 vph, 4 Hz
Lift Angle	51 degrees (unconfirmed)
Power Reserve	42 hours
Rotor Style	Ball-bearing
Rotor Winding Direction	Bi-directional
Hand-Windable?	Yes
Anti-Shock Device	Incabloc
Hand Count	3
Functions	Central hours; central minutes; central sweeping seconds; date at 6:00
Hacking Seconds?	Yes
Country of Manufacture	Switzerland, Swiss made
Known Models	Ulysse Nardin Diver (ref: 8163-175-7M/92, 8163-175-7M/93, 8163-175-7MIL/92), Limited Edition Lemon Shark Diver (ref: 8163-175LE/92-LEMONSHARK) (Add your watch to the comments below…)

The Ulysse Nardin caliber UN-816 is a basic 3-hander automatic watch movement with a date. This caliber is found in various models of the brand’s Diver collection (which, at the time of this post contains 27 watches with the UN-816).

Base Movement:

The UN-816 uses the Sellita calibre SW300-1 (which itself is a clone of the ETA 2892-A2) as the base movement.

Upgrades to the base include a silicium (silicon) escapement wheel and anchor.

For some reason, UN only seems to provide an image of the dial side of the movement, but at least from that we can see the Sellita SW300-1.

Other than the difference in datewheel to accommodate the 6:00 date window on UN-816 watches, visual differences in the in the side-by-side comparison image above are mostly caused by photographic lighting and reflections.

Caliber Number:

You may see this caliber number written as UN816, UN-816 or UN 816 – even Ulysse Nardin doesn’t seem to maintain consistency with the caliber spelling, with a hyphenated “UN-816” on their product pages, and no hyphen on the Lemon Shark press page.

Additional Resources:

• Official UN-816 user manual (pdf)