CORPUS EXPORT · 12269 calibers · 59387 family views · round round/2026-09-08Compiled from app/public/data/ · corpus 70c0140eba.
Family treeBifora 51 — Heritage family: 2 calibers, 1 sourced lineage link.Drag to explore.
accepteddisputed

movement

Bifora 51

Biforaarchive filingintroduced 1960design:bifora-51compare specs · 2

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
Bifora 51
movementproducer: Biforaarchive filing
IIDesignations — 0 names

No designation is recorded for this design yet.

IIIExecutions — 1 article

No source in this corpus states which grade any Bifora 51 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:bifora-51/unknown

Specifications

PropertyValueScopeStatusSources
Jewels
build.jewel_count
17—staged
Movement shape
build.shape
rectangular—staged
Movement height
geom.height_mm
3.2 mm—staged
Frequency
osc.frequency_vph
18000 vph—staged
Shock protection
osc.shock_protection
otherexample movement, 1970staged
Discontinued
prod.discontinued_year
1966—staged
Introduced
prod.intro_year
1960—staged
Winding mode
wind.mode
manual—staged

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.

Descendants · 1

What came from it — revisions, variants, clones, licensed copies.

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.

Sources

  1. 1
    Internet Archive
    https://web.archive.org/web/20230905140756/http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&0&2uswk&Bifora_51&
    archivetier 2retrieved 2023-09-059 facts on this page
  2. 2
    Internet Archive
    https://web.archive.org/web/20181106133135/http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&a0&2uswk&Dugena_1203
    archivetier 2retrieved 2018-11-061 fact on this page