Short answer
IW371642 is a reference in the IWC Portugieser Chronograph line. Steel case, 41 mm. Silver-plated dial with gold-plated markers and leaf hands. In-house calibre 69355, 46-hour power reserve, no date. Replicas of this reference exist at several grades. The parts that fail are case thickness, subdial function, dial printing and movement finish. No replica carries a real IWC 69355.
Reference facts
- Case: stainless steel, 41 mm diameter, about 13.1 mm thick per IWC.
- Dial: silver-plated, two subdials. Small seconds at 6. 30-minute counter at 12. No date window.
- Hands and markers: gold-plated, applied.
- Crystal: sapphire front and back. Water resistance 3 bar.
- Movement: calibre 69355, automatic, 4 Hz, 46 hours.
- Strap: brown alligator, 20 mm lugs.
Tells on replicas
Thickness and weight
Ask the seller for a caliper photo across the caseback and crystal. A 41 mm Portugieser case sits near 13 mm. Many fakes run 14.5 mm to 15 mm because the base movement needs a module. Weight tracks thickness. A steel case of this size lands near 80 g on the strap, and fakes with a thin case often land lower.
Subdial function
On the real watch the chronograph drives the 30-minute counter at 12. On many fakes the 12 o'clock subdial is a 24-hour or day/night display, and the hand stays parked. Request a short video: start the chronograph, let it run two minutes, and watch the hand at 12 advance two marks. The small seconds at 6 must sweep with the watch running.
Dial printing
Check the spacing of "IWC", "SCHAFFHAUSEN" and the numerals. Fakes show thick strokes, uneven gaps and markers that sit off the printed track. The silver-plated dial has a light, even sheen. Replicas use a flat white or a heavy sunburst.
Fake IW371642: What the Best Copies Get Right
Caseback and movement
The sapphire back shows a skeletonized rotor and Geneva stripes on the bridges. Fakes show a plain rotor, coarse perlage and stamped text. Compare the caseback engraving depth and the reference number placement.
Strap and clasp
IWC alligator has tight, small scales and cut edges. Fake straps are thicker, with square scales and a glossy finish. Stitch pitch and buckle engraving are easy to compare side by side.
Checks before you pay
- Caliper photo of case thickness.
- Video of the chronograph running, with the 12 o'clock counter moving.
- Clear photo of the movement through the caseback.
- Dial macro shot at an angle, not straight on.
- Photo of the caseback engraving.
- Return policy in writing.
What no replica gets right
Water resistance and service access. A replica case is not pressure tested to 3 bar, and no watchmaker will stock parts for a cloned movement. Treat any replica as splash resistant. Price is the other gap: this reference trades on the secondary market near its retail level, so a low asking price points to a fake, not a deal.