Sinn 856 B-Uhr Limited Edition Watch 856.012

The Sinn 856 B-Uhr Limited Edition represents a masterful blend of historic aviation design and cutting-edge German engineering. Limited to just 856 pieces worldwide, this exceptional timepiece continues the legacy of traditional observer watches while incorporating Sinn’s renowned technological innovations for unparalleled durability and performance.

Condition: Excellent pre-owned condition
Includes: Original box and papers
Guarantee: Dated November 2019
Shipping: Free UK delivery

Sinn 856 B-Uhr Key Features

Historic B-Uhr Heritage

• Authentic observer watch design inspired by historic deck watches
• Distinctive dial layout with emphasised minute hand for quick readability
• Reduced hour hand pointing to separate inner hour circle
• Ivory-coloured luminescent coating on numerals, indices, and triangular marker
• Traditional B-Uhr configuration prioritising minutes for operational use
• Limited to 856 pieces with individual numbering on caseback

Advanced Sinn Technology

• TEGIMENT Technology creating a scratch-resistant hardened steel surface
• Ar-Dehumidifying Technology preventing fogging and enhancing reliability
• Magnetic Field Protection up to 100mT (80,000 A/m) minimising interference
• Sapphire crystal glass with anti-reflective coating on both sides
• 200m water resistance for exceptional durability
• Low pressure resistant for aviation use

Precision Engineering

• Swiss Sellita SW300-1 automatic movement
• 28,800 semi-oscillations per hour for smooth operation
• 25 bearing jewels ensuring reliability
• Seconds stop function for precise time setting
• Anti-magnetic protection as per DIN 8309
• 38-hour power reserve

Refined Construction

• Perfectly proportioned 40mm bead-blasted stainless steel case
• Comfortable 11mm case thickness for everyday wearability
• Premium tan brown calfskin leather strap
• Screw-down crown ensuring water resistance
• Nickel-free caseback for sensitive skin
• Lightweight 70g case (without strap)

The Sinn Advantage

Sinn Spezialuhren, founded by pilot and instructor Helmut Sinn in 1961, has established itself as a premier manufacturer of high-performance tool watches. Based in Frankfurt am Main, the company combines traditional German engineering principles with innovative technologies developed in-house. Under the leadership of Lothar Schmidt since 1994, Sinn has pioneered advances such as TEGIMENT hardening technology and Ar-Dehumidifying systems that set their timepieces apart from conventional luxury watches.

Perfect For

• Aviation enthusiasts appreciating authentic pilot watch heritage
• Watch collectors seeking limited edition German timepieces
• Professionals requiring exceptional durability and readability
• Those valuing technical innovation with historical design elements
• Anyone seeking a distinctive tool watch with proven reliability

Frequently Asked Questions

What is the historical significance of B-Uhr watches?

The term “B-Uhr” (Beobachtungsuhr, or “observation watch”) originated with the navigational timepieces used by military pilots and navigators, particularly during World War II. These watches featured distinctive characteristics including large cases for legibility, prominent minute scales, and clear numerical indices. The emphasis on minutes over hours was crucial for navigation calculations and mission timing. This Sinn 856 B-Uhr continues this tradition while incorporating modern watchmaking advances.

What makes TEGIMENT Technology special?

TEGIMENT Technology is Sinn’s proprietary surface hardening process that significantly increases the scratch resistance of the stainless steel case. Unlike coatings that can chip or peel, TEGIMENT creates a hardened surface layer that is integrated with the base material. This results in a watch that maintains its appearance despite the rigours of daily wear. The process increases the surface hardness to approximately 1200 Vickers (standard stainless steel ranges from 200-400 Vickers).

How does the Ar-Dehumidifying Technology work?

Sinn’s Ar-Dehumidifying Technology uses a combination of special seals, protective gas filling, and a copper sulphate capsule to keep the movement environment free of moisture. The copper sulphate capsule (visible as a small dot, typically in the side of the case) actively absorbs any moisture that might enter the watch, preventing internal fogging and reducing the ageing of oils within the movement. This system enhances long-term reliability, particularly in changing climate conditions.

What level of magnetic field protection does this watch offer?

With protection up to 100mT (millitesla) or 80,000 A/m (amperes per meter), the Sinn 856 B-Uhr offers exceptional resistance to magnetic fields encountered in everyday environments. This level of protection exceeds standard anti-magnetic watches and shields the movement from interference caused by electronic devices, speakers, magnetic closures, and even some medical equipment, ensuring consistent timekeeping accuracy regardless of environment.

How does the 40mm case size compare to historical B-Uhr watches?

Traditional B-Uhr watches used during WWII typically featured very large cases, often 55mm or larger, to maximise legibility in cockpit conditions. Sinn has thoughtfully reduced the size to a more wearable 40mm diameter while maintaining the distinctive design elements and legibility of the historical originals. This modernised proportion makes the watch suitable for everyday wear while honouring its heritage.

What is the significance of the 856-piece limitation?

The production limit of 856 pieces relates directly to the model number (856 B-Uhr) and creates exclusivity for collectors. This numbered limitation is permanently recorded via individual engraving on each watch’s caseback. As Sinn limited editions typically sell out relatively quickly, this restricted production enhances both collectability and potential long-term value.