Front view
Dial, hands and bezel as delivered.
Case-back view
Case-back engraving and, where fitted, the sapphire display.
Movement
Calibre with its finishing and decoration.
On the wrist
Worn shot for proportion and strap drape.
Sinn · 556
Sinn 556 36 mm Mother-of-pearl 18k
Reference 43846OR.55
Reference at a glance
- Brand
- Sinn
- Collection
- 556
- Model
- Sinn 556 36 mm Mother-of-pearl 18k
- Reference number
- 43846OR.55
- Year / era
- 1976 · 1970s — quartz-crisis era
- Complication
- Flyback chronograph
- Movement
- Automatic COSC chronometer
- Case material
- 18k rose gold
- Dial type
- Mother-of-pearl
- Strap / bracelet
- Alligator leather with folding clasp
- Water resistance
- 50 m
- Limited-edition status
- Regular production, not a limited edition
Case, dial & bracelet
- Case dimensions
- 36 mm
- Case thickness
- 11.3 mm
- Case material
- 18k rose gold
- Bezel
- Octagonal with 8 hexagonal screws
- Crystal
- Anti-reflective sapphire, double-domed
- Dial
- Mother-of-pearl
- Hands
- Skeletonised sword hands, white luminescent
- Indexes
- Applied Roman numerals
- Bracelet / strap
- Alligator leather with folding clasp
- Clasp / buckle
- Titanium deployant clasp
- Water resistance
- 50 m
Movement
- Movement / calibre
- Calibre 74B — Automatic COSC chronometer
- Movement type
- Manual-winding
- Frequency
- 21,600 vph (3 Hz)
- Power reserve
- 72 hours
- Number of jewels
- 40 jewels
- Complications
- Flyback chronograph
- Functions
- Hours, minutes, seconds, date
- Watchmaker
- Finishing, assembly and timing are carried out in the manufacture's own atelier.
Production & market
- Production period
- 1976 – 1984
- Limited-edition quantity
- Not applicable
- Current market information
- Thin secondary-market supply — pricing is set piece by piece at auction.
Designer
In-house design studio
The reference was drawn by the manufacture's internal design office, where case, dial and movement architects work alongside the watchmakers rather than as an outside commission.
Historical significance
Sinn 556 36 mm Mother-of-pearl 18k sits within Sinn's 556 line, introduced in 1976. It carries the house codes established since 1961 — 18k rose gold case, mother-of-pearl dial and automatic cosc chronometer — and is one of the references collectors use to date the evolution of the collection.
Interesting facts
- The reference was originally planned as a one-year run and stayed in the catalogue for well over a decade.
- The bracelet tapers across its length, which is why the profile looks thinner on the wrist than the specification suggests.
The House
Sinn
Brand facts
- Founding year
- 1961
- Founder
- Helmut Sinn
- Headquarters
- Germany
- Tier
- Affordable & Tool Watches
- Major collections
- 556, 104, EZM, U1, 903, Hydro
- Signature technologies
- Anti-magnetic silicon escapement · Shock-absorbing movement mounting
- Famous movements
- Automatic, 38-hour reserve · Automatic Powermatic 80 · Automatic COSC chronometer · Quartz
- Notable watches
- Sinn 556 42 mm Silvered 18k (1975) · Sinn 556 43 mm Slate Sapphire (1961) · Sinn 556 36 mm Mother-of-pearl 18k (1976) · Sinn 556 43 mm Ice 18k (1965)
Brand history
Sinn has spent more than 65 years refining a single idea: a watch should outlive its owner. From the earliest workshop pieces to today's 556, the house has balanced technical ambition with a recognisable design language, and its collections remain among the most closely followed by collectors worldwide.
Helmut Sinn established Sinn in 1961, working from Germany at a time when precision was measured by hand. The founder's obsession with finishing and accuracy still defines every Sinn calibre produced today.
Historical milestones
1961
Helmut Sinn founds Sinn in Germany.
1969
The quartz era forces Sinn to redefine mechanical watchmaking.
1990
Sinn enters the modern collector market with its signature lines.
2024
Sinn continues to produce 556, 104, EZM and other icons in limited numbers.