Sinn · Instrument Watches

Strap for Pilot's Watch 856 S UTC

Takes 20 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.

Lug width20 mm
Case diameter40 mm
Reference856.020
FamilyInstrument Watches
MovementETA caliber 2893-2 hours, minutes, seconds, Additional 24 hours Hand (adjustable) | date
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 Instrument Watches 856.020

Selected for the 20 mm lug width · workshop selection

All 20 mm straps →

The Instrument Watches 856.020, seen from the bench

The Sinn 856.020 from the Instrument Watches collection is equipped with the ETA 2893-2 caliber with hour, minute, second, adjustable GMT hand and date functions. The watch has 20mm lugs. The movement provides a second time zone indication through the adjustable 24-hour hand.

Frequently asked questions

What is the correct lug width for the Sinn Instrument Watches 856.020?

The lug width of the Sinn 856.020 is 20 millimetres. This measurement is taken between the inner edges of the spring bar receptacles and ensures compatibility with the vast majority of contemporary artisanal watch straps, from NATO-style nylon bands to bespoke leather straps.

Which strap type pairs best with the Sinn 856.020?

The Sinn 856.020 is particularly complemented by natural vegetable-tanned leather straps in cognac or black, which create an elegant contrast with the brushed steel case, or NATO-style straps in canvas or ballistic nylon to emphasize its instrumental vocation. For water sports or maritime use, a vulcanised rubber strap offers superior practicality.

How do I change the strap on the Sinn Instrument Watches 856.020?

Remove the spring bars by means of a dedicated fork-shaped tool. Position the watch on a soft surface, insert the tool tip into the spring bar apertures, gently push toward the centre to release the pin, extract the old strap and install the new one by aligning it with the holes. The 20mm lug width ensures universal compatibility with all straps of this dimension.

Does the Sinn 856.020 accept quality aftermarket straps?

Absolutely. With a 20mm lug width, the 856.020 is entirely compatible with artisanal aftermarket straps in leather, alligator, shell cordovan and technical textiles. Selecting straps crafted by specialised artisans allows you to completely personalise the watch's appearance and adapt it to different occasions and seasons.

What is the typical lifespan of a leather strap on the Sinn 856.020?

A quality leather strap on a daily-worn watch typically lasts 3-5 years, depending on tanning method, sun exposure, ambient humidity and cleaning frequency. Vegetable-tanned leather straps develop a natural patina over time and tend to age gracefully; regular maintenance—gentle cleaning and conditioning—significantly extends service 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