NOMOS Caliber DUW 4101

Brand	NOMOS Glashütte
Caliber Number	DUW 4101, DUW4101
Based On	NOMOS beta
In-House?	Yes
Movement Type	Mechanical, manual-wind
Linges	14.25”’
Diameter	32.1mm
Height	2.8mm thick
Jewels	26
Beat Rate	21,600 vph, 3 Hz
Power Reserve	42 hours
Shock System	Incabloc
Features	NOMOS Swing System, Glashütte stopwork, adjusted in six positions
Functions	Central hours; central minutes; small seconds at 6:00; date at 6:00 below the small seconds (available in two colors: dark charcoal background with white text or white background with black text – depending on the watch)
Hacking Seconds?	Yes
COSC?	No
Finishing	Rhodium-plated surfaces with Glashütte ribbing, NOMOS perlage, ratchet and crown wheel with Glashütte sunburst, tempered blue screws
Country of Manufacture	Germany
Known Models	Metro 38 Date (Ref: 1102), Metro 38 Date Urban Gray (Ref: 1103), Tengente 38 Date (Ref: 130), Ludwig 38 Date (Ref: 231), Orion 38 Date (ref: 380), Orion 38 Date White (Ref: 381)

The NOMOS Glashutte caliber DUW 4101 is an in-house mechanical manual-wind watch movement with 23 jewels. This caliber is made in Germany. The DUW 4101 was announced in 2015 in the Metro 38 Datum and is still a current caliber being used in the NOMOS catalog as of 2023. The design and functionality of this caliber is an evolution of its predecessor: NOMOS beta (β).

In the brand’s own words:

“This hand-wound caliber features an extra-large date, the NOMOS swing system, and a great deal of tradition—such as beautiful polishings that are unique to Glashütte.” –source

Swing System:

The DUW 4101 is equipped with the proprietary NOMOS Swing System escapement. This is the brand’s own in-house design/invention. When mentioning their Swing System in marketing materials, NOMOS uses the word “independence” frequently. This part appears to be the brand’s escape(ment) from dependency on parts from the Swiss conglomerates (such as Swatch Group).

As NOMOS says:

“A NOMOS caliber with swing—since DUW 4101 also features the groundbreaking escapement that has become famous: the NOMOS swing system (recognizable by the blue balance spring). With this component, described as “a moon landing” by the press, our Glashütte-based watchmaking company broke the Swiss monopoly on production in 2014.” –source

DUW 4101 Dial Side:

Image Credit: The image at the top of this post was captured in-person by Caliber Corner at Baselworld 2015 during a press meeting at the NOMOS booth. All other images are copyright of NOMOS Glashütte and are featured by Caliber Corner for educational and informational purposes.

Additional Resources:

• NOMOS DUW 4101 official page
• NOMOS Swing System
• More NOMOS calibers