A fake IW371425 is a replica of the IWC Portugieser chronograph that carries reference number IW371425. The fastest way to separate a fake from the real thing is to compare four areas against IWC's official specification for that exact reference: the movement, the dial printing, the case finishing, and the caseback engraving.
What the IW371425 reference actually is
IWC builds the Portugieser chronograph in several dial and case combinations, and each one receives its own reference number. IW371425 is one of those combinations. Because the differences between them are small, a buyer who only knows the model name can end up with the wrong watch or a copy of the wrong watch. Before you compare anything, look up the reference on IWC's site and note the case diameter, case metal, dial color, strap type, and calibre. That list becomes your checklist.
Why this model gets copied so often
The Portugieser chronograph has a clean, readable dial with thin applied markers and two registers. That simplicity works against counterfeiters. There is very little decoration to hide behind, so the details that remain have to be executed well. Thin markers, narrow hands, and a large open dial all magnify small errors in printing, polishing, and alignment.
Dial and hands
- Printing: check the sharpness of the brand text and the railway track minute scale. Genuine printing is crisp under magnification. Copies often show thicker strokes, uneven spacing, or edges that bleed.
- Markers: applied indices should sit level, at consistent height, and reflect light evenly. Look for markers that are tilted, sit too proud, or have rough polishing on the sides.
- Hands: leaf style hands should be evenly finished with clean edges. On many fakes the hands are too thick or show tool marks.
- Registers: subdial spacing and hand lengths should match reference photos exactly. Check that each subdial hand reaches the correct point on the scale.
- Date window: the aperture should be cleanly cut with even borders, and the date font should suit the period of the reference.
Case, crystal and crown
Case finishing separates good replicas from bad ones. Run a fingertip along the line where a brushed surface meets a polished one. On a genuine IWC the transition is a straight, defined edge. On a fake it is often soft, wavy, or polished over by mistake. The crystal should be clear with no haze or distortion at the edges when you tilt the watch under a light. The crown should turn smoothly, and on a chronograph the pushers should have a firm, defined click rather than a mushy press.
Movement
This is the hardest part to fake and the easiest to verify. Ask for a clear photo of the movement through the caseback, then compare the layout to the calibre IWC lists for the reference. Look at the shape of the bridges, the position of the screws, and the engraving on the rotor or bridges. Many replicas use a stock chronograph movement with a different bridge layout and a different power reserve. If the seller will not show the movement, treat the watch as unknown.
Caseback, serial number and paperwork
Caseback engraving is a common weak point. Reference numbers, serial numbers, and case metal stamps should be cut cleanly and sit on a consistent baseline. Look for shallow laser etching, uneven letter heights, or a reference number that does not match the dial and case configuration. A genuine box and papers help, but they can be copied too, so treat them as supporting evidence rather than proof.
A practical checking order
- Confirm the reference number and pull the official specification.
- Compare dial photos side by side at full magnification.
- Check case finishing at the brushed and polished transitions.
- Ask for movement photos and match the bridge layout.
- Compare caseback engraving with known examples of the same reference.
- Have an independent watchmaker open the case before money changes hands.
What replica grades mean
Sellers often label replicas by grade, and the labels vary from one seller to the next. What matters in practice is what was actually built: the movement inside, the material of the case, and the quality of the dial printing and finishing. Ask specific questions about those three things instead of relying on a grade name.
Used together, these checks catch most fakes of the IW371425. The dial and the movement do most of the work.