Fake IW371435: start here

The reference IW371435 is an IWC Portugieser Chronograph. If you are searching for a fake one, or checking whether the watch in front of you is genuine, the decisive details are these: the real watch carries a two-register dial with the chronograph counter at 12 and running seconds at 6, a sapphire display back, and an automatic chronograph movement. Counterfeits copy the front well enough to fool a photo, then fail at the back of the watch. Before you spend anything, ask for clear photos of the caseback, the movement, the serial engraving, and any paperwork. Listings that show only the dial, or that reuse press images instead of photos of the actual unit, are the ones to leave alone.

What the genuine IW371435 is

  • Case: stainless steel, approximately 40.9 mm across and about 12.3 mm thick, with 20 mm lugs.
  • Dial: two subdials stacked on the vertical axis, chronograph minutes at 12, small seconds at 6, applied numerals, leaf shaped hands, railway style minute track.
  • Movement: automatic chronograph. Earlier production used a modified Valjoux 7750 base, later production moved to an in-house calibre with a column wheel and vertical clutch. Hours of power reserve differ between the two, so confirm which build you are looking at.
  • Crystal: sapphire front and back. The display back is the single most useful check on this reference.
  • Water resistance: modest for the line, in the region of 3 bar on most versions.
  • Strap: leather on a steel pin buckle, with case matched hardware.

Confirm the exact dial colour and strap option against IWC's own page for the reference, because those details changed across the production run.

Checks that separate real from fake

  • Caseback. A genuine IW371435 has a sapphire display back with crisp engraving. Many counterfeits ship with a solid steel back or a sapphire back that shows a stock chronograph movement with no IWC finishing, no Geneva stripes, and a rotor that is a printed plate.
  • Chronograph feel. Push the chronograph start and stop. A column wheel movement feels light and clean and the seconds hand starts with no jump. A modified 7750 feels heavier. Cheap copies use quartz or a basic automatic chronograph and the pushers feel gritty or spongy.
  • Subdial behaviour. The running seconds at 6 should sweep in small steps. If the small seconds at 6 ticks once per second, the watch is quartz and the reference is being faked.
  • Dial printing. Look at the text under high magnification. Genuine printing has sharp edges and consistent weight. Copies show fuzzy edges, uneven spacing, and a logo that sits slightly off centre.
  • Hands and markers. Leaf hands should be polished on the top surface with a clean bevel. Applied numerals sit flush with a sharp shadow line. Glued or painted markers are a warning sign.
  • Case dimensions. Measure with a caliper. A 42 mm or 44 mm case wearing the IW371435 reference is not the watch it claims to be.
  • Weight. Steel cases of this size have a settled heft. Counterfeits using plated brass or a thinner case feel light in the hand.
  • Papers and serial. The serial on the caseback should match the paperwork, and the paperwork should look like it came from a dealer rather than a printer.

Numbers worth checking before you commit

  • Diameter: about 40.9 mm. Anything from 42 mm upward is wrong.
  • Thickness: about 12.3 mm. Very thin cases point to a quartz copy.
  • Lug width: 20 mm.
  • Chronograph counter: 30 minutes at 12 o'clock.
  • Running seconds: at 6 o'clock, sweeping, not ticking.
  • Caseback: sapphire display, not solid steel.

Pitfalls in the replica market

The trade in counterfeit watches is a federal matter in the United States, and shipments are subject to seizure at the border. Buyers have no warranty, no access to IWC service, and no resale value. Independent watchmakers often decline to work on counterfeit movements because parts are unavailable. Listings that promise a "super clone" or a "1:1 AAA" grade are marketing language with no standard behind it, and the same seller often ships a different watch than the one photographed. Frankenwatches, meaning genuine cases fitted with copied dials or movements, are the hardest to spot and the most expensive mistake. A short service history with a named watchmaker is worth more than any grading label.

FAQ

Is a fake IW371435 a good buy? It holds no resale value, cannot be serviced by IWC, and carries legal and customs risk. If the goal is a two-register chronograph look, there are legitimate alternatives at several price points.

How do I check one I already own? Take it to a watchmaker and have the caseback opened. Movement finishing, rotor engraving, and calibre markings settle the question in minutes.

Can a counterfeit pass as genuine online? Yes, which is why photos of the movement and caseback matter more than any dial shot.

What is the first red flag? A price far below the market for the reference, combined with a seller who will not open the caseback on camera.