Nomos Glashütte · Tetra

Strap for Tetra Goldelse

Takes 18 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.

Lug width18 mm
Case diameter30 mm
Reference491
FamilyTetra
MovementNomos Glashütte caliber Alpha hours, minutes, small seconds
Year2014
CaseStainless Steel

Spring bar

Swiss Standard universal spring bars

The right category for this model · 316L steel, all lug widths 13–26 mm

Straps for the Tetra 491

Selected for the 18 mm lug width · workshop selection

All 18 mm straps →

The Tetra 491, seen from the bench

The Nomos Glashütte Tetra 491 is a square-case watch with 29.50mm diameter, powered by the Nomos Glashütte Alpha caliber beating at 21,600 alternations. The stainless steel case features a scratch-resistant sapphire crystal and visible movement through the caseback. The 18mm lug width is a precise construction choice that maintains proportions on this compact diameter, designed for leather straps in alligator or Italian calf or cotton NATO fabrics that respect the watch's minimalist design.

Frequently asked questions

What is the lug width of the Nomos Glashütte Tetra 491?

The lug width of the Nomos Glashütte Tetra 491 is 18mm. This is a non-standard measurement, precisely calculated by Nomos to maintain perfect proportions on a 29.50mm case diameter. Verifying the distance between the lug holes with a digital calliper allows you to confirm compatibility before purchasing an aftermarket strap.

What is the best strap for the Nomos Glashütte Tetra 491?

The best strap choice depends on your intended use and aesthetic philosophy. An alligator strap with vegetable tanning enhances the minimalism of the 491 with tactile elegance. Italian calf leather offers softness whilst maintaining perfect visual proportions. A NATO in raw cotton is ideal for sporty daily wear. An FKM rubber strap delivers fluidity and all-weather versatility. The right choice is one that reflects your lifestyle and primary context of use.

How do you change the strap on the Nomos Glashütte Tetra 491?

To change the strap, use a spring bar tool or fine needle to depress the spring-loaded terminals of the lug pins. Holding the case on a stable surface, gently push the pin sideways until it disengages. The new strap must have the same insertion holes for 18mm pins. Perform the operation with patience to avoid case scratches: if uncertain, consult a professional watchmaker.

Are aftermarket straps compatible with the Tetra 491?

Yes, any strap with an 18mm lug width is compatible with the Nomos Glashütte Tetra 491. The crucial detail is verifying that the insertion holes match the case width and that the strap shoulders do not create visible friction with the case flanges. Quality artisanal straps can be custom-tailored to guarantee a perfect fit.

How long does a leather strap last on the Tetra 491?

A quality leather strap, with periodic maintenance, typically lasts 2–4 years of daily wear. Longevity depends on frequency of use, sun exposure, humidity, and leather type: an alligator or vegetable-tanned calf naturally develops patina and ages elegantly. It is advisable to rotate multiple straps periodically and apply protective balms to extend the material's working life.

The next step

The right strap isn't chosen. It is built, together.

From the atelier appointment to delivery, every step is made for those who know that things done well take time. Rare leathers, one piece at a time, eighteen months of warranty.

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Casati Milano · Via XX Settembre 15, Milan · by appointment only