Short answer
A fake IW371470 is a counterfeit of an IWC Portugieser Chronograph from the 3714 reference family. Genuine watches in this family use Swiss calibre 79350, a modified Valjoux 7750. Copies use Asian movements, most often a 7750 clone or a Seagull ST19. Case size, subdial spacing, caseback engraving, and price are the fastest tells.
IW371470 is one suffix in a long list of 3714 references that differ by dial, hands, and strap. IWC does not publish a separate spec sheet for every suffix. Confirm the dial color and strap code for this number with IWC or an authorized dealer before you compare a watch against it.
Price gap
Genuine steel Portugieser Chronographs sell new between about $7,000 and $9,000. Replicas sell between $250 and $600. A private listing at one fifth of market price is a copy, a stolen watch, or a scam. No exception exists for this reference.
Case and dial checks
- Diameter: 40.9 mm on 3714-family watches. Many copies measure 41.5 mm or 42 mm.
- Thickness: about 12.3 mm. Thin copies use a slimmer chronograph module.
- Subdials: chronograph minutes at 12, running seconds at 6, date at 3. Copies place the subdials wider or narrower than the genuine dial.
- Numerals: applied metal, polished, with sharp edges. Printed numerals mark a copy.
- Hands: leaf-shaped, polished on both flanks. Copies show tool marks and uneven edges.
- Crystal: sapphire with anti-reflective coating on both faces. Mineral glass scratches and shows no coating tint.
- Crown and pushers: signed crown, precise threads, no side play.
Movement and caseback
Ask for a clear photo of the movement through the display back. Genuine calibre 79350 has engraved IWC markings, a signed rotor, and clean finishing. Copies show rough grinding, blank bridges, or a printed logo that flakes.
Rotor feel is not proof. A 7750-based copy winds with the same unidirectional weight shift as the genuine base movement. Use the engraving, not the shake, to judge.
Check the caseback: depth of engraving, font of the reference number, and the case number. Both numbers should appear, and both should match the paperwork.
Paperwork and seller signals
Genuine examples come with a box, a warranty card, and a serial that matches the caseback. An IWC boutique or authorized service center can check a serial against its records. A watch with no card, from a private seller, at a price under $1,000, is not genuine. Some sellers describe replicas openly as a clone or super clone. That wording is honest and the price should match it.
U.S. Customs and Border Protection seizes counterfeit watches at import. A shipment can be destroyed and the buyer can lose the money with no refund.
Checks before you pay
- Match the reference and case number to the card.
- Run the chronograph: start, stop, reset. The hands should snap back to zero.
- Weigh the watch head. Steel is denser than the brass and zinc alloys in low-cost copies.
- Request service history. A recent IWC service invoice is hard to fake.
- Pay with a method that allows a chargeback, or use an escrow service.
What stays unknown
IWC does not run a public serial database, so a serial check depends on a boutique or service center. Dial variants for some 3714 suffixes appear in the used market without manufacturer documentation. Treat any listing that cannot show a matching card and a movement photo as unverified.