CALIBER/browser
CORPUS EXPORT · 12269 calibers · 59387 family views · round round/2026-09-08Compiled from app/public/data/ · corpus 70c0140eba.
Family treeBifora 691 — Heritage family: 4 calibers, 3 sourced lineage links.Drag to explore.
100%drag to pan · hover a caliber to isolate its line · scroll the page normallyopen the full family view →
ébauche ofébauche ofébauche ofBifora 691 — the caliber this page is aboutBifora 6911968Bifora1 exec · grade ?Dugena 2001 (Bifora 691) — open caliber pageDugena 2001 (Bifora 691)—maker not sourced1 exec · grade ?Dugena 2002 (Bifora 691) — open caliber pageDugena 2002 (Bifora 691)—maker not sourced1 exec · grade ?Dugena 713 (Bifora 691) — open caliber pageDugena 713 (Bifora 691)—maker not sourc…1 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

Bifora 691

Biforaarchive filingintroduced 1968design:bifora-691compare specs · 4
bounding evidence — no range is drawn on the era axis
not after 1973
a dated example movement, ca. 1968 (+5 yr, the source says “circa”)“ca. 1968: Dugena 713; Bifora-Bishock”

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 691
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 691 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-691/unknown

Specifications

PropertyValueScopeStatusSources
Jewels
build.jewel_count
17—staged
Movement shape
build.shape
rectangular—staged
Movement height
geom.height_mm
3.5 mm—staged
Frequency
osc.frequency_vph
21600 vph—staged
Shock protection
osc.shock_protection
otherexample movement, 1968staged
Power reserve (typical)
power.reserve_typical_h
40 h—staged
Introduced
prod.intro_year
1968—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.

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/20230905144253/http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&0&2uswk&Bifora_691&
    archivetier 2retrieved 2023-09-0510 facts on this page
  2. 2
    Internet Archive
    https://web.archive.org/web/20230907003809/http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&0&2uswk&Dugena_2001&
    archivetier 2retrieved 2023-09-071 fact on this page
  3. 3
    Internet Archive
    https://web.archive.org/web/20230907004103/http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&0&2uswk&Dugena_2002&
    archivetier 2retrieved 2023-09-071 fact on this page
  4. 4
    Internet Archive
    https://web.archive.org/web/20230907054541/http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&0&2uswk&Dugena_713&
    archivetier 2retrieved 2023-09-071 fact on this page