Quick answer
The IW371472 is an IWC Portugieser Chronograph reference. A fake fails on four measurable points: case size and thickness, the bicompax subdial layout with running seconds at 6 and chronograph minutes at 12, the leaf-shaped hands, and the engraving and finish on the caseback. Measure the case first. Copies usually drift by half a millimetre or more, and that error is visible the moment you set the watch next to the catalog photo. Confirm the exact numbers for this reference on the IWC site before you judge anything, because IWC tweaks specs between variants.
Prerequisites
- Digital calipers
- 10x jeweller's loupe
- Catalog photos of the genuine reference
- Bright, indirect light
- A phone camera for macro shots
Step-by-step check
- Measure the case across the bezel and from caseback to crystal. The genuine watch sits near 41 mm wide and between 12 and 13 mm thick, so treat any reading outside that band as a warning.
- Measure lug to lug and lug width. Fakes often stretch the lug span to fit off-the-shelf straps, which throws off the case proportions.
- Compare the subdial positions. The chronograph minutes sit at 12 and the running seconds at 6, and both counters should be identical in diameter with the same distance from the centre.
- Check the dial furniture with the loupe. Applied numerals have a raised edge and a polished bevel, while printed numerals sit flat and catch light differently.
- Inspect the hands. The leaf-shaped hour and minute hands taper to a point and carry a clean polish on the top facet, with no burrs along the edge.
- Look at the date aperture at 3 o'clock. The cut should be square, the frame crisp, and the disc printed in the same colour family as the dial.
- Flip the watch and read the caseback engraving. Letter spacing, depth and font weight should match the reference number, and the movement number should be legible under a loupe.
- Study the movement through the display back. Look for Geneva stripes, blued screws, a signed oscillating weight and clean perlage on the plates.
- Run the chronograph. Start, stop and reset the sweep a few times and watch whether the pushers return with a firm, short click.
- Weigh the price against the secondary market. A genuine IW371472 trades for thousands of dollars, so a listing in the low hundreds is a copy no matter what the seller claims.
Where cheap copies fail
Low-grade fakes get the silhouette roughly right and nothing else. The tell is usually the dial wording, where the text spacing runs tight or wide against the printing on the genuine watch. Next comes the bracelet or strap hardware, which feels light and shows sharp edges on the clasp. Subdial hands on cheap builds are often the wrong length, stopping short of the printed track.
Replica grades and what they change
Replica IW371472 builds sit in tiers. Entry versions use a generic quartz or a basic automatic with a decorated rotor. Mid-tier versions add a clone chronograph movement, sapphire crystal and closer case finishing. Top-tier versions chase case dimensions, dial printing and hand finishing, and they usually accept a genuine-spec strap. The higher the tier, the more of the ten checks above the watch passes.
Red flags at a glance
- Seller photos shot only from the front
- No caseback image
- No measurement stated for case diameter
- Stock catalog images used as the listing photo
- Price far below the secondary market