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The Encyclopedia of Horology

Wristwatch · Center seconds wristwatch

IWC Ref. 2400 Stainless Steel Wristwatch

Partially verified

This water-resistant wristwatch, referenced 2400, was produced by International Watch Co. in the 1970s. Housed in a two-body 'Staybrite' stainless steel case measuring 34 mm in diameter and 9.5 mm in thickness, the watch features a polished and brushed finish with an inclined bezel and a screwed-down case-back. It is presented on an integral stainless steel mesh bracelet. The watch is powered by the manual-wind Calibre C.403 movement, which is rhodium-plated and decorated with fausses cotes. The movement comprises 17 jewels, a straight-line lever escapement, and a monometallic balance adjusted to three positions, equipped with a shock absorber and a micrometer regulator. The satiné silver dial displays applied steel faceted baton indexes and outer minute divisions, complemented by steel baton hands. The watch, including the dial, case, and movement, is signed by the manufacturer.

Front view of the International Watch Co. Ref. 2400 in stainless steel, featuring a silver dial and integral mesh bracelet.
Front view of the International Watch Co. Ref. 2400 in stainless steel, featuring a silver dial and integral mesh bracelet. — Antiquorum. Rights pending — permission not yet requested. Original source

Catalogue identity

Source
catalog.antiquorum.swiss
Category
Wristwatch · Center seconds wristwatch
Maker / attribution
International Watch Co.
Reference
2400
Catalogue / lot identifier
555
Source-reported date
1970s
Source-reported place
Switzerland
Source-reported serial
2175438

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 constructed with a two-body 'Staybrite' stainless steel case measuring 34 mm in diameter and 9.5 mm in thickness. The exterior features a combination of polished and brushed surfaces, accompanied by an inclined bezel. Access to the movement is provided via a screwed-down case-back. The watch is completed by an integral stainless steel bracelet.

The dial is finished in a satiné silver tone and is adorned with applied steel faceted baton indexes. Outer minute divisions are present around the perimeter. Time is indicated by steel baton hands. The dial, case, and movement are signed by the manufacturer.

Evidence for this section
  • “Two-body, polished and brushed, screwed-down case-back, inclined bezel.”
  • “Satiné silver with applied steel faceted baton indexes, outer minute divisions. Steel baton hands.”
  • “Dial, case and movement signed.”

Movement and Escapement

The watch operates on the IWC Calibre C.403, a manual-wind movement. The movement is finished with rhodium plating and features fausses cotes decoration. The construction includes 17 jewels and a straight-line lever escapement.

Technical features of the caliber include a monometallic balance adjusted to 3 positions, a shock absorber system, a self-compensating flat balance spring, and a micrometer regulator for precise adjustment.

Evidence for this section
  • “Cal. C.403, rhodium-plated, fausses cotes decoration, 17 jewels, straight line lever escapement”
  • “monometallic balance adjusted to 3 positions, shock absorber, self-compensating flat balance spring, micrometer regulator.”

Condition and Authenticity

The auction description provides a grade of 'A' for the item. The case is described as being in good condition with minor signs of wear, specifically noted as 'slightly scratched'. The dial is also evaluated as being in good condition.

Regarding the internal components, the auction report specifies that the original hands are present.

Evidence for this section
  • “Grade: A Good”
  • “Case: 3-8 Good Slightly scratched”
  • “Movement: 3* Good Overhaul recommended, at buyer's expense”
  • “HANDS Original”

Open research questions

  • What is the specific production year within the 1970s for this movement number?
  • Was the integral bracelet the original model-matched configuration as sold by IWC at the time of manufacture?

Source evidence

Recorded claims and source quotations for IWC Ref. 2400 Stainless Steel Wristwatch
FieldSource-reported valueSource quotation
MakerInternational Watch Co., Schaffhausen“International Watch Co., Schaffhausen”
Reference2400“Ref. 2400”
Case MaterialStaybrite stainless steel“'Staybrite' stainless steel”
Movement CaliberC.403“Cal. C.403”
Jewel Count17“17 jewels”
Case Diameter34 mm“Diam. 34 mm”
Serial (Case)2175438“case No. 2175438”
Serial (Movement)2158953“movement No. 2158953”

Visible details

  • Integral mesh-style metal bracelet
  • Applied baton hour markers
  • Plain baton-style hands
  • Textured silver dial surface

Research qualifications

  • Condition report indicates the movement requires an overhaul
  • The case shows slight scratches

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

Consulted source

IWC Ref. 2400 Stainless Steel International Watch Co., Schaffhausen, movement No. 2158953, case No. 2175438, Ref. 2400. Made in the 1970s. Fine, water-resistant, center seconds, 'Staybrite' stainless steel wristwatch with an integral stainless steel IWC bracelet.

Reviewed 2026-10-26 · Record e93c53e506

Terms in this record

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

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