A fake IW371407 is a counterfeit of the IWC Portugieser Chronograph reference IW371407, a 40.9 mm stainless steel chronograph with two subdials stacked at 12 and 6 o'clock and an IWC calibre 79350 inside. The four fastest tells are a case thicker than about 12.5 mm, soft or misaligned dial printing, a plain Valjoux 7750 with no IWC finishing, and any date window at 3 o'clock, which the genuine reference never had. Confirm all four before you judge anything else.
What is the IW371407?
The IW371407 belongs to the Portugieser Chronograph family, a line IWC has built in roughly the same 40.9 mm case since the late 1990s. It runs the calibre 79350, a Valjoux 7750 base that IWC rebuilds with its own finishing, and it carries two subdials at 12 and 6 o'clock with no date.
Because the base movement is a 7750, the subdial layout of a replica can match the original exactly. That makes the IW371407 one of the easier references to fake and one of the harder ones to spot from a photo alone.
What are the most common tells on a fake IW371407?
Case size and thickness
The genuine case measures 40.9 mm across and about 12.3 mm thick, with a slim bezel and short, downturned lugs. Most replicas run 41.5 to 42 mm and 13.5 to 15 mm thick because the 7750 and its rotor need more room.
Sit the watch flat on a table. A genuine Portugieser Chronograph sits low, while a fake IW371407 often stands taller than the strap line.
Dial printing and hands
Check the SCHAFFHAUSEN text under the logo, the minute track, and the space between the two subdials. Genuine printing is thin, black, and sharp under magnification, while replicas show thickened strokes, ink bleed, or a minute track that drifts off the chapter ring.
The leaf shaped hands should be mirror polished on top with softly brushed sides. Fake hands are often flat, too short, or sit too close to the dial.
Movement and finishing
Where the back is see through, compare the rotor engraving. IWC signs the oscillating weight and finishes the bridges with Geneva stripes, perlage, and blued screws, while a stock 7750 shows plain matte plates and a generic rotor.
Case back and serial engraving
Reference and serial numbers sit between the lower lugs and should be crisp and evenly spaced. Replicas frequently reuse the same serial across batches, engrave with a laser that leaves a burnished edge, or stamp a reference that does not match the dial and hands.
How do replica grades differ?
- Entry tier: quartz or low grade automatic, wrong case size, mineral glass, painted subdials.
- Mid tier: 7750 clone, closer proportions, sapphire crystal, visible printing errors.
- High tier: correct 40.9 mm case, AR coated sapphire, decorated 7750 with an IWC style rotor, closest to the real watch in photos.
Price tracks these tiers. A high tier replica costs many times an entry level one and still uses a movement that is not built to IWC tolerances.
What should you check on a replica IW371407 before buying?
- Ask for the measured case diameter and thickness with calipers, not the listed spec.
- Request macro photos of the dial text, the subdial hands, and the case back engraving.
- Confirm which movement is inside and whether the chronograph resets to zero.
- Check the strap and clasp hardware for sharp edges and correct branding depth.
- Compare every photo against official IWC reference images for that exact dial variant.
Does the IW371407 have a date window?
No. The Portugieser Chronograph uses two subdials and no date, so any 3 o'clock aperture is a strong sign of a fake or of a different reference being sold as an IW371407.
Can a fake IW371407 be told apart by weight and feel?
Often yes. Genuine steel cases carry a solid heft, and the winding, pusher action, and crown threads feel damped rather than gritty. A replica frequently feels lighter in the case and rougher at the pushers, especially at the start and stop points of the chronograph.