Eberhard & Co Age determination by year of manufacture Chronographs
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Eberhard & Co. Clocks, founded in 1887 in La Chaux-de-Fonds
| Period | Events / Characteristics |
|---|---|
| 1887 | Founded by Georges-Emile Eberhard in La Chaux-de-Fonds |
| 1900–1920 | Fine pocket watches, silver/gold case, engraving “Eberhard & Co. – Chaux-de-Fonds” |
| 1920–1940 | Transition to wristwatches, introduction of the chronograph lines – calibers 13 ¼'' and 15 ½'' |
| 1930s | Patented chronographs with separate start/stop and reset functions, serial numbers from approximately 200,000. |
| 1940–1950 | “Extra-Fort” series – Eberhard’s trademark (trigger + reset via 2 buttons) |
| 1950–1970 | Automatic chronographs / Eberhard Cal. 14000 family |
| 1970–1990 | Mechanical & Quartz Epics (“Scientigraf”, “Chronomaster”) |
| 1990–present | Luxury collections (“Chrono 4”, re-editions Extra-Fort, etc.) |
Serial and work numbers – orientation table
Eberhard used consecutive serial numbers on the cases (usually inner or outer case back) of hand-held and wristwatches, plus separate movement numbers (from the movement manufacturer, e.g. Valjoux, Lemania, FHF, AS).
Only the case number reflects the Eberhard production.
| Case/serial number (approx.) | Estimated timeframe | Typical models / calibers |
|---|---|---|
| < 50,000 | 1890 – 1915 | Pocket watches, brass/silver cases |
| 50,000 – 150,000 | 1915 – 1930 | Early wristwatches, FHF/AS basis |
| 150,000 – 250,000 | 1930 – 1938 | First chronographs (manual movement Eberhard 13 ¼'') |
| 250,000 – 350,000 | 1938 – 1945 | “Extra-Fort”, single-pusher chronographs |
| 350,000 – 450,000 | 1945 – 1955 | “Extra-Fort” two-pusher chronograph (Valjoux 65, Eberhard Cal. 14000) |
| 450,000 – 600,000 | 1955 – 1965 | Bracelet/automatic models (AS 1361N, ETA 2472) |
| 600,000 – 800,000 | 1965 – 1975 | “Scientigraf”, “Contograph” |
| 800,000+ | after 1975 | more modern series (automatic / quartz) |
🧭 Example:
An “Eberhard & Co. Extra-Fort” with case number 317 xxx → ca. 1943–1945.
Movement caliber as a time indicator
| caliber | Origin / Type | Dating | use |
|---|---|---|---|
| Eberhard 13 ¼'' / 15 ½'' | In-house development | 1930–1940 | Early single-pusher chronographs |
| Eberhard Cal. 14000 / 14003 / 14009 | Manufacture chronographs | 1940–1955 | “Extra-Fort” |
| Valjoux 65, Valjoux 72, Valjoux 7730 | Supplied chronograph calibers | 1950–1970 | Contograf, Chrono 41 |
| ETA 1080, 2472, 2783 | Automatic three-hand watch | 1955–1975 | Standard automatic models |
| Lemania 1873 / EB Cal. 310/1361N | Manual winding / Automatic | 1960–1980 | "Scientigraf" wristwatches |
| ETA 2892 / Valjoux 7750 / Eberhard 31011 | Automatic / Chronograph | 1980 – today | Modern series |
Identifying features per era
| feature | Period |
|---|---|
| Hand-signed engraving “Eberhard & Co. – Chaux-de-Fonds” | before 1930 |
| Fraktur font / Ornate logo | 1930 – 1945 |
| Block logo “EBERHARD & Co – SWISS” | 1950 – 1970 |
| Logo “Eberhard & Co” with italic lettering + crown symbol | from 1980 |
| Glass floor / ETA factory | after 1990 |
Identify movement (caliber)
| Caliber / Movement | Chronological context |
|---|---|
| Eberhard Cal. 16000, 16009 | 1950s–60s |
| Venus 175, 188 (Chronographs) | 1940s–1960s |
| Valjoux 72 (Chronograph) | 1960s–1970s |
| ETA 2892, 7750, Unitas 6497 | 1980s–present (various models) |
| Eberhard 8 Jours (manufactured movement) | from 1997 (special spring barrel construction) |
Model and design features for age determination
| Feature / Model | Chronological context |
|---|---|
| “Extra-Fort” Chronographs | from around 1940s (Venus 175, Valjoux 72) |
| Pre-Extra-Fort pocket chronographs | 1920s–30s |
| Scafograf 100 / 200 / 300 | 1960s (diving watches, highly sought after today) |
| 8 days | from 1997 (manual winding with 8-day movement) |
| Tazio Nuvolari Series | from the 1990s onwards – sporty/racing-inspired |
Design tips:
-
Large chronographs with two pushers → mostly from 1940 onwards
-
Gold cases with enamel dial → often 1920s–30s
-
Luminous indices + diver's bezel → Scafograf series (1960s)
-
Visible back, modern engravings → mostly after 1995
| name | Year of manufacture | Housing | dial | clockwork | function |
|---|---|---|---|---|---|
| Eberhard (Chronograph with one pusher) | 1920 | Yellow gold | White | Mechanical with manual winding | Chronograph |
| Eberhard (Extra-fort) | 1950 | Yellow gold | Silver | Mechanical with manual winding | Chronograph |
| Eberhard (8-day model) | 1997 | Steel | Silver | Mechanical with manual winding | Power reserve of 8 days |
Using the production years/calibers of chronographs, it may be possible to roughly estimate the age of an Eberhard&Co watch:
1920s single-pusher chronograph, manual winding, white dial, yellow gold
1935 Chronograph Extra Fort, Cal 110, manual winding, gold-plated metal
1936 Valjoux Cal 65, 17 jewels, manual winding, rose gold plated
1938 first "Eberhard&Co Chronograph, hand-wound, movement gilt, dial gold"
1938 Chronograph Valjoux Cal 65, 18K with hinged case, white dial
1940 Valjoux Cal 65, two-pusher chronograph, 18K gold, tachymeter scale, 2 subdials
1945 Chronograph Valjoux 72, 18K, 17 jewels, 3 subdials
1950 Extra Fort Chronograph, manual winding, yellow gold, silver dial
1960 Valjoux 7768, stainless steel, moon phase, limited to 989 pieces
1987 Caliber 14, sterling silver case, 21 jewels, limited to 4000 pieces
1989 Valjoux Cal 7751, chrome-plated metal, full calendar/moon phase, limited edition of 999 pieces
1990 Valjoux Cal 7751, gold-plated, automatic, full calendar, moon phase
1990 Lemania caliber 872, 17 jewels, gold-plated stainless steel
1997 "8 Days", mechanical, hand-wound, silver dial, stainless steel
Source: Wolfgang Salm "Wristwatches", Wikipedia, AI
