FEF 6631

Update

Basic Information

NameFEF 6631
ManufacturerFabrique d'Ébauches de Fleurier
Launch Year1970
Caliber FamilyDescription
short plate edges straight:
6600: 18000 A/h, setting-lever screw
6620: 21600 A/h, setting-lever screw
6630: 21600 A/h, setting-lever button
6632: 21600 A/h, redesigned click
6700: 28800 A/h, setting-lever button
6710: 21600 A/h, second, setting-lever button
6720: 28800 A/h, second, setting-lever button

short plate edges round:
6621: 21600 A/h, setting-lever screw
6631: 21600 A/h, setting-lever button
6633: 21600 A/h, redesigned click
6701: 28800 A/h, setting-lever button
6711: 21600 A/h, second, setting-lever button
6721: 28800 A/h, second, setting-lever button

Related calibers
FEF 6600, FEF 6620, FEF 6621, FEF 6630, FEF 6631, FEF 6632, FEF 6633, FEF 6700, FEF 6701, FEF 6710, FEF 6711, FEF 6720, FEF 6721
Is COSC certifiedNo

Technical Details

Lignes Dimensions5.75 ‴ x 6.75 ‴
Dimensions13.05 mm x 15.55 mm
Height3.5 mm
Further MeasuresMounting Diameter (Dm): 13.05 x 15.15mm
Stem height (T): 1.7mm
Mounting Height (F): 0.6mm
Power Reserve45 hours
Frequency21,600 vph
Jewels21
Lift Angle52 degrees

Complications and Specifications

ShapeCushion
Complications
  • Year Calendar
Shock ProtectionIncabloc
Regulator TypePinned Regulator (or Index Regulator)
Movement TypeManual
Escapement TypeSwiss Lever
Control TypeBalance Wheel
Winding TypeStem Winding (Crown)
Setting TypeStem Set (Crown Pull)

Additional Information

Hand Sizes1.00 x 0.55mm
Hand Count2
Country Of ManufactureSwitzerland
NotesOther data: balance staff: U3124 / U3513 without/with shock device stem: W3393 mainspring / battery: Zf1181, 1.50 x 6.0 x 0.065 x 195mm
Ranfft mentioned about this caliber: There are variants with this quantity of jewels 17, 21
Signature1-2) ca. 1970: Swiss, 21 Jewels; Incabloc 3-4) ca. 1980: 504-424, Girard-Perregaux, Swiss, 17 Jewels; Kif-Ultraflex

Metadata

Created AtSep 15, 2023
Updated AtApr 23, 2025, 11:32:27 PM