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The Encyclopedia of Horology

Wristwatch · Manual-wind wristwatch

Patek Philippe Calatrava Reference 3720J

Partially verified

This Patek Philippe Calatrava, reference 3720J, is a manually wound wristwatch produced circa 1985. The timepiece features a 32 mm case constructed from 18k yellow gold, characterized by a flat, thin bezel and a screw-down case back. The dial is finished in a white tone, incorporating black printed Roman numeral hour markers and non-luminous stick-style hands. Internally, the watch is driven by the ultra-thin, hand-wound calibre 177 movement. The piece is presently mounted on a leather strap manufactured by Bulang & Sons. The auction description reports that the watch has undergone a service by their watchmaker. This reference is identified by the movement serial number 136xxxx and a case number recorded as 279xxxx. It represents an iteration of the long-standing Calatrava model line from the mid-1980s period.

The Patek Philippe Calatrava 3720J in 18k yellow gold, featuring a white dial with Roman numerals.
The Patek Philippe Calatrava 3720J in 18k yellow gold, featuring a white dial with Roman numerals. — Bulang & Sons. Rights pending — permission not yet requested. Original source

Catalogue identity

Source
www.bulangandsons.com
Category
Wristwatch · Manual-wind wristwatch
Maker / attribution
Patek Philippe
Reference
3720J
Catalogue / lot identifier
Source URL identifies the listing
Source-reported date
circa 1985
Source-reported place
Not established
Source-reported serial
279xxxx

Source-reported attribution and specifications are not independent authentication. A listing does not establish present ownership, current display, availability or permission to reproduce.

Object description

Case and Dial

The watch is housed in a 32 mm case crafted from 18k yellow gold. The exterior architecture of the timepiece includes a flat, thin bezel paired with a screw-down case back, intended to secure the internal components.

The dial surface provides a white background intended to contrast with the black printed Roman numeral hour markers. Time is indicated via two non-luminous stick-style hands, which correspond to the hour and minute functions. The dial includes the text 'PATEK PHILIPPE GENÈVE' below the twelve o'clock position and 'SWISS' at the bottom of the dial surface.

Evidence for this section
  • “32 mm 18k yellow gold case, a flat and thin bezel, a screw -back case back”
  • “White dial with black printed Roman numerals and non-lumed stick hands”

Movement and Function

The watch is powered by the calibre 177 movement. This is a hand-wound, ultra-thin mechanism. The movement is specified as the primary timekeeping component for this reference 3720J model.

The documentation confirms the movement serial number as 136xxxx. The watch has been subjected to a service process by the vendor's internal watchmaker to prepare it for distribution.

Evidence for this section
  • “Powering the watch is the legendary hand-wound ultra-thin calibre 177.”
  • “Cal.177 hand wound movement”
  • “movement serial 136xxxx”
  • “Fully serviced by our watchmaker”

Identification and Provenance

This object is catalogued as a mid-1980s Patek Philippe Calatrava, bearing the reference number 3720J. The specific identification numbers associated with this individual watch include a case number 279xxxx and a movement serial number 136xxxx, which together suggest a production date of approximately 1985.

The watch is presently configured with a Bulang & Sons leather strap.

Evidence for this section
  • “This mid-1980's Ref. 3720”
  • “Case no 279xxxx movement serial 136xxxx , dating to circa 1985”
  • “Bulang and sons leather strap”
  • “One-year mechanical warranty”

Open research questions

  • Confirm the correct assignment of the 279xxxx and 136xxxx serial numbers between the case and movement.
  • Investigate the cause of the staining visible on the hands to determine if it is oxidation or debris.

Source evidence

Recorded claims and source quotations for Patek Philippe Calatrava Reference 3720J
FieldSource-reported valueSource quotation
MakerPatek Philippe“Patek Philippe Calatrava Reference 3720J”
Reference3720J“Patek Philippe Calatrava Reference 3720J”
Case Material18k yellow gold“32 mm 18k yellow gold case”
MovementCalibre 177“Cal.177 hand wound movement”
Datingcirca 1985“dating to circa 1985”
Case Serial279xxxx“Case no 279xxxx”
Movement Serial136xxxx“movement serial 136xxxx”
DialWhite“White dial with black printed Roman numerals”

Visible details

  • Case and bezel are 18k yellow gold
  • Dial features non-lumed stick hands
  • Black Roman numerals are printed on the dial
  • Leather strap has white contrast stitching

Research qualifications

  • Movement serial number listed as 279xxxx or 136xxxx requires clarification in source
  • Discolouration or staining is visible on the hands in photos

Photograph identity and source facts were screened before import; rights clearance remains pending.

Consulted source

Patek Philippe Calatrava 3720J White Dial in 18 k Yellow Gold

Reviewed 2026-11-02 · Record 1f7e1beccd

Terms in this record

Glossary explanations for terms named in this object’s record.

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