A fake IW371625 is a replica of the IWC Portugieser Chronograph reference IW371625, and the quickest way to identify one is to examine the movement, the dial printing, and the caseback engraving. Authentic examples run on an IWC chronograph caliber with a signed rotor and finishing that replica workshops rarely reproduce. Everything else, from crown action to strap stitching, is supporting evidence that either confirms or contradicts what the movement shows.
What the IW371625 actually is
The reference belongs to the Portugieser Chronograph line, a stainless steel bicompax chronograph with a clean dial that places elapsed chronograph minutes at 12 o'clock and running seconds at 6 o'clock. Most watches in the family measure about 41 mm across, use a sapphire crystal on both sides, and skip the date window that appears on many competing chronographs.
Exact dial color, strap choice, and case finish vary by reference number, so confirm the specification for IW371625 on the manufacturer's own listing rather than trusting a seller's description. One frequent source of confusion is the movement generation. Earlier Portugieser Chronograph references used a modified outsourced chronograph base, while later ones moved to an in-house IWC caliber. A replica seller who mixes up those generations is often working from a copy of a catalog photo rather than the watch itself.
Where replicas give themselves away
Movement and caseback
Open the caseback or look through a display back and study the rotor, the bridges, and the engraving. Genuine IWC movements show crisp lettering, Geneva stripes or circular graining applied evenly, and blued or polished screws that sit flush. Replica chronographs usually hide an Asian-made chronograph movement behind a decorated plate, and the decoration tends to look stamped rather than cut. Caseback text is another giveaway: reference numbers, serial numbers, and case material markings should be engraved with consistent depth and alignment, not printed faintly or spaced unevenly.
Dial and hands
The Portugieser dial is simple, which makes small errors obvious. Check that the applied numerals sit level, that the printed minute track stays the same distance from the chapter ring all the way around, and that subdial hands reach the correct part of their tracks. On fakes, the subdials are often slightly too large or placed a fraction low, the date is missing where it should be absent, and the hands show a rougher bevel under angled light.
Case, crown, and pushers
Run a fingertip along the case flanks. Original IWC cases have crisp transitions between brushed and polished surfaces, while replicas often show a soft or wavy line where the two finishes meet. The crown should turn with light, even resistance and pull out with a distinct click. Chronograph pushers should start, stop, and reset with a short, positive throw and no grinding.
Strap, buckle, and paperwork
Strap stitching should be straight and evenly spaced, with a signed pin buckle or deployant clasp whose engraving matches the caseback lettering. Boxes, manuals, and warranty cards are easy to counterfeit and are therefore weak evidence on their own. Treat paperwork as a bonus, not proof.
How the first copy market fits in
Sellers who deal in first copy watches use that term to describe higher-grade replicas built to look convincing at arm's length. The category still sits far below the price of an authentic Portugieser Chronograph on the secondary market, and that gap is the simplest reality check. If a listing for an IW371625 claims original parts, recent service history, and a factory-fresh condition at a price that undercuts every other example you can find, the watch is almost certainly a fake IW371625 rather than a bargain.
Checks to run before you pay
- Photograph the reference and serial engraving and compare it with a verified example of the same reference.
- Ask for a movement photo with the caseback removed, or a clear shot through the display back.
- Confirm the chronograph starts, stops, and resets at the correct positions on the subdials.
- Measure the case diameter and thickness with calipers if you can handle the watch in person.
- Compare dial proportions against the manufacturer's own product images at the same angle.
- Have a watchmaker inspect the movement before the return window closes.
Common questions
Can a fake IW371625 fool a jeweler?
At a glance, sometimes. Under a loupe, no. Movement finishing, engraving depth, and dial print quality are the details that hold up to magnification, and replicas consistently lose there.
Is the strap a reliable clue?
Only as supporting evidence. Straps get replaced often, so a worn or aftermarket strap on an otherwise correct watch means little.
Does a certificate make a watch genuine?
No. Certificates and boxes are among the easiest items to copy. The movement and case engraving carry the real weight.
The short version
A fake IW371625 reveals itself through the movement, the caseback engraving, and the precision of the dial. Buy from a seller who will show you the movement, document the reference number clearly, and allow an inspection period. When the price, the paperwork, and the finishing all point the same direction, you have your answer.