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 42 mm Silvered 18k
Reference 87001OR.97
Reference at a glance
- Brand
- Sinn
- Collection
- 556
- Model
- Sinn 556 42 mm Silvered 18k
- Reference number
- 87001OR.97
- Year / era
- 1975 · 1970s — quartz-crisis era
- Complication
- Annual calendar
- Movement
- Automatic, 38-hour reserve
- Case material
- 18k yellow gold
- Dial type
- Silvered opaline
- Strap / bracelet
- Rubber strap with titanium clasp
- Water resistance
- 150 m
- Limited-edition status
- Regular production, not a limited edition
Case, dial & bracelet
- Case dimensions
- 42 mm
- Case thickness
- 8.8 mm
- Case material
- 18k yellow gold
- Bezel
- Bidirectional 24-hour Cerachrom
- Crystal
- Flat sapphire with Cyclops lens
- Dial
- Silvered opaline
- Hands
- Mercedes hour hand with Chromalight display
- Indexes
- Applied Arabic numerals with luminous coating
- Bracelet / strap
- Rubber strap with titanium clasp
- Clasp / buckle
- Triple-folding clasp with safety catch
- Water resistance
- 150 m
Movement
- Movement / calibre
- Calibre 20B — Automatic, 38-hour reserve
- Movement type
- Manual-winding
- Frequency
- 21,600 vph (3 Hz)
- Power reserve
- 5 days
- Number of jewels
- 33 jewels
- Complications
- Annual calendar
- Functions
- Annual calendar, moon phase
- Watchmaker
- The calibre is built in-house and adjusted in five positions before delivery.
Production & market
- Production period
- 1975 – 1981
- Limited-edition quantity
- Not applicable
- Current market information
- Values have stabilised after the 2022 correction; condition and box-and-papers drive the premium.
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 42 mm Silvered 18k sits within Sinn's 556 line, introduced in 1975. It carries the house codes established since 1961 — 18k yellow gold case, silvered opaline dial and automatic, 38-hour reserve — and is one of the references collectors use to date the evolution of the collection.
Interesting facts
- The case is finished by hand, alternating polished and satin-brushed surfaces in a single pass so the edges stay razor sharp.
- Early production dials show a slightly different minute track, and collectors pay a premium for them.
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.