Durowe 7420/2 (INT)

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Basic Information

NameDurowe 7420/2 (INT)
Alternative NameINT 7420/2
ManufacturerDurowe
Launch Year1975
Caliber FamilyDescription
10.5" manual wind:
7410: -
7411: 24h hand
7412: date

11.5" manual/automatic respectively:
7420/7520: -
7421/7521: 24h hand
7422/7522: date
7423/7523: day, date
7424/7524: minute stop feature
7425/7525: date quickset
7426/7526: day, date quickset
7427/7527: day at 9h, date quickset
7428/7528: date, month calendar, quickset
- /7539: date, digital
7430...7438 like 7420...7428, but jumping second
7530...7538 like 7520...7528, but jumping second
suffix /1: modification quickset date
suffix /2: minor modifications
suffix /3: modification click spring

Related calibers
Durowe 7410 (INT), Durowe 7410/2 (INT), Durowe 7411 (INT), Durowe 7411/2 (INT), Durowe 7412 (INT), Durowe 7412/2 (INT), Durowe 7420 (INT), Durowe 7420/2 (INT), Durowe 7420/3 (INT), Durowe 7421 (INT), Durowe 7421/2 (INT), Durowe 7421/3 (INT), Durowe 7422 (INT), Durowe 7422/2 (INT), Durowe 7422/3 (INT), Durowe 7423 (INT), Durowe 7423/2 (INT), Durowe 7423/3 (INT), Durowe 7424 (INT), Durowe 7424/2 (INT), Durowe 7424/3 (INT), Durowe 7425 (INT), Durowe 7425/1 (INT), Durowe 7425/2 (INT), Durowe 7425/3 (INT), Durowe 7426 (INT), Durowe 7426/1 (INT), Durowe 7426/2 (INT), Durowe 7426/3 (INT), Durowe 7427 (INT), Durowe 7427/1 (INT), Durowe 7427/2 (INT), Durowe 7427/3 (INT), Durowe 7428 (INT), Durowe 7428/1 (INT), Durowe 7428/2 (INT), Durowe 7428/3 (INT), Durowe 7520 (INT), Durowe 7520/2 (INT), Durowe 7520/3 (INT), Durowe 7521 (INT), Durowe 7521/2 (INT), Durowe 7521/3 (INT), Durowe 7522 (INT), Durowe 7522/2 (INT), Durowe 7522/3 (INT), Durowe 7523 (INT), Durowe 7523/2 (INT), Durowe 7523/3 (INT), Durowe 7524 (INT), Durowe 7524/2 (INT), Durowe 7524/3 (INT), Durowe 7525 (INT), Durowe 7525/1 (INT), Durowe 7525/2 (INT), Durowe 7525/3 (INT), Durowe 7526 (INT), Durowe 7526/1 (INT), Durowe 7526/2 (INT), Durowe 7526/3 (INT), Durowe 7527 (INT), Durowe 7527/1 (INT), Durowe 7527/2 (INT), Durowe 7527/3 (INT), Durowe 7528 (INT), Durowe 7528/1 (INT), Durowe 7528/2 (INT), Durowe 7528/3 (INT), Durowe 7539 (INT)
Is COSC certifiedNo

Technical Details

Lignes Dimensions11.5 ‴
Dimensions26 mm
Height3.8 mm
Further MeasuresMounting Diameter (Dm): 25.6mm
Stem height (T): 1.9mm
Mounting Height (F): 1.1mm
Power Reserve42 hours
Frequency21,600 vph
Jewels17

Complications and Specifications

ShapeRound
Complications
  • Sweep Second
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 Sizes1.50 x 0.90 x 0.21mm
Hand Count3
Country Of Manufacture(not set)
NotesRemarks: 7 jewels combined with plastic bearings for the balance likely exclusive for Hamilton military watches
Other data: balance staff: U3224 stem: W3278 mainspring / battery: Zf869, 1.30 x 9.5 x 0.105 x 300mm
Ranfft mentioned about this caliber: There are variants with this quantity of jewels 7, 17
Signatureca. 1975: INT 7420/2, 17 Jewels; Rufa-Anti-Shock

Metadata

Created AtSep 15, 2023
Updated AtMay 26, 2026, 4:43:48 AM