CALIBER/browser
CORPUS EXPORT · 12269 calibers · 59387 family views · round round/2026-09-08Compiled from app/public/data/ · corpus 70c0140eba.
Family treeETA 1256 — Heritage family: 4 calibers, 3 sourced lineage links.Drag to explore.
100%overlaydrag to pan · hover a caliber to isolate its line · scroll the page normallyopen the full family view →
ébauche ofébauche ofébauche ofDugena 603 (ETA 1256) — open caliber pageDugena 603 (ETA 125…1950maker not sourced1 exec · grade ?ETA 1256 — the caliber this page is aboutETA 12561950ETA SA Manufacture Horlogère…1 exec · grade ?Girard-Perregaux 47 (ETA 1256) — open caliber pageGirard-Perregaux 47 (ETA 125…1950maker not sourced1 exec · grade ?Girard-Perregaux 47BF (ETA 1256) — open caliber pageGirard-Perregaux 47BF (ETA 1…1950maker not sourced1 exec · grade ?
accepteddisputed
Sense of “family”Heritage · 4Everything (debug) · 4Parts cluster (Jules Borel sense) · 1Manufacturer-internal (Ranfft sense) · 1Based-on star (WatchBase sense) · 4Open the full family view →

movement

ETA 1256

ETA SA Manufacture Horlogère Suissearchive filingintroduced 1950design:eta-1256compare specs · 4
bounding evidence — no range is drawn on the era axis
not after 1955
a dated example movement, ca. 1950 (+5 yr, the source says “circa”)“1-2) ca. 1950: Swiss Made, 21 Jewels; Incabloc”

Identity

A caliber is three separate things and this reference keeps them apart: the construction, the names it is sold under, and the article a brand actually bought. A watch model points at an execution — never at a bare construction — which is why “same caliber” is almost never a complete answer.

IDesign — the construction
ETA 1256
movementproducer: ETA SA Manufacture Horlogère Suissearchive filing
IIDesignations — 0 names

No designation is recorded for this design yet.

IIIExecutions — 1 article

No source in this corpus states which grade any ETA 1256 was bought at. That unknown is stored as a real row rather than left blank, so it can be counted, filtered and excluded from any comparison that would otherwise assume parity.

unknownsynthetic
evidence: unknown

no source states which grade this article was bought at — this row exists so 'unknown' stays countable instead of becoming an assumption

exec:eta-1256/unknown

Specifications

PropertyValueScopeStatusSources
Jewels
build.jewel_count
17Ranfft data sheet, the 17-jewel member of its 17/21/25 rangestaged
Jewels
build.jewel_count
21Ranfft data sheet, the 21-jewel member of its 17/21/25 rangestaged
Jewels
build.jewel_count
25Ranfft data sheet, the 25-jewel member of its 17/21/25 rangestaged
Seconds display
disp.seconds_display
central—staged
Casing diameter
geom.casing_diameter_mm
26 mm—staged
Movement diameter
geom.diameter_mm
25.6 mm—staged
Frequency
osc.frequency_vph
18000 vph—staged
Shock protection
osc.shock_protection
incablocexample movement, 1950staged
Power reserve (typical)
power.reserve_typical_h
40 h—staged
Discontinued
prod.discontinued_year
19541256...1259staged
Introduced
prod.intro_year
19501256...1259staged
Production volume
prod.volume_count
117601021256...1259staged
Winding mode
wind.mode
automatic—staged

Where a property carries more than one value, the values have different scopes — an official spec sheet and observed hardware, say. Different scopes are not a disagreement, so both are accepted and both are shown with the scope they apply to.

Lineage

The same relationships as the tree at the top of this page, with their sources. An absence in a column means no source stated one.

Ancestors · 0

Where this construction came from. Read up the arrows.

None recorded. An absence here means no source stated one, not that none exists.

Related · 0

Stored in a different table from descent. A successor is not a child.

None recorded. An absence here means no source stated one, not that none exists.

Curated family labels

ETA family/generations block
authority: ranfft50 members

Sources

  1. 1
    Internet Archive
    https://web.archive.org/web/20220704160117/http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&0&2uswk&ETA_1256
    archivetier 2retrieved 2022-07-0415 facts on this page
  2. 2
    Internet Archive
    https://web.archive.org/web/20190826065400/http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&0&2uswk&ETA_1081
    archivetier 2retrieved 2019-08-261 fact on this page
  3. 3
    Internet Archive
    https://web.archive.org/web/20191121125757/http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&0&2uswk&ETA_1084
    archivetier 2retrieved 2019-11-211 fact on this page
  4. 4
    Internet Archive
    https://web.archive.org/web/20191121153441/http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&0&2uswk&ETA_1082
    archivetier 2retrieved 2019-11-211 fact on this page
  5. 5
    Internet Archive
    https://web.archive.org/web/20191122195052/http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&0&2uswk&ETA_1083
    archivetier 2retrieved 2019-11-221 fact on this page
  6. 6
    Internet Archive
    https://web.archive.org/web/20191215185342/http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&0&2uswk&Dugena_603
    archivetier 2retrieved 2019-12-151 fact on this page
  7. 7
    Internet Archive
    https://web.archive.org/web/20120419055632/http://www.ranfft.de/cgi-bin/bidfun-db.cgi?03&ranfft&0&2uswk&Girard-Perregaux_47
    archivetier 2retrieved 2012-04-191 fact on this page
  8. 8
    Internet Archive
    https://web.archive.org/web/20191117152752/http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&0&2uswk&Girard-Perregaux_47BF
    archivetier 2retrieved 2019-11-171 fact on this page