A fake IW371642 usually fails at the subdials first. On a genuine IWC Portugieser Chronograph, the 30-minute counter at 12 and the small seconds at 6 sit perfectly on the vertical axis through the crown, the printing is crisp and slightly raised, and the date aperture at 3 is cut with a chamfered frame. Replicas drift off-axis by a fraction of a millimeter, and that error is visible in any straight-on photo.
What does the genuine IW371642 look like?
The IW371642 belongs to the 3716 family of Portugieser Chronographs, a 41 mm steel watch with a slim bezel, feuille hands, applied Arabic numerals, and a railway minute track. Inside sits the in-house calibre 69355, a column-wheel chronograph with roughly 46 hours of power reserve and a sapphire caseback. Confirm the exact dial and strap configuration for the reference you are buying, because IWC has issued several dial variants across the 3716 production run.
Case and proportion checks
- Diameter should measure 41 mm, thickness about 13 mm, with a lug width near 20 mm.
- The bezel is thin and polished, and the caseband alternates brushed and polished surfaces with tight transitions.
- Lugs curve downward and taper cleanly, with no tool marks or rounded edges where the caseback meets the mid-case.
How do you spot a fake dial?
Start with a loupe at 10x and look at the printing under raking light. Genuine IWC text is applied with sharp edges and consistent stroke width, while replica printing looks soft, uneven, or slightly thick at the serifs. The applied numerals should sit flat with polished bevels that catch light along one edge only.
Next, check the hands. The feuille hands on a genuine watch are diamond-cut with a crisp central ridge and a flawless leaf silhouette, and the chronograph seconds hand resets to zero instantly and repeatably. On a fake, the hands often look flat, the ridge is rounded, and the reset hesitates or overshoots.
How do you verify the movement through the caseback?
A genuine 3716 shows a column-wheel chronograph with a signed rotor, Geneva stripes or circular graining as specified for the calibre, and cleanly engraved bridge text. Replicas commonly hide a modified third-party chronograph module, a decorated cover plate, or a rotor engraving that uses the wrong typeface and depth.
Ask for a macro photo of the balance area and the chronograph bridge. If the seller refuses, or the movement shows a regulator index instead of a free-sprung balance, treat the watch as suspect.
What do the strap, clasp, and packaging reveal?
IWC alligator straps are hand-stitched with even spacing, a soft supple hand, and a signed pin buckle or deployant clasp with crisp engraving. Fake straps typically feel stiff, use square machine stitching, and carry shallow laser-etched branding. Box, warranty card, and booklet should match the reference and serial, and the card should show a legible dealer stamp and date.
Does weight and feel give a replica away?
Weight alone is not conclusive, since a steel replica can land within a few grams of the original. What matters more is the winding feel, the crisp click of the chronograph pushers, and the smooth, slightly resistant twist of the crown. A genuine 69355 starts cleanly with a firm column-wheel engagement, while most fakes feel mushy or grind.
What should the price tell you?
Any offer far below the prevailing secondary market range for a steel Portugieser Chronograph deserves scrutiny, especially from a private seller with stock photos. Verify the serial against IWC service records, request a dated video of the running chronograph, and use a payment method with buyer protection.