A fake IW371620 is almost always a copy of the IWC Portugieser Chronograph built on a decorated ETA or Valjoux 7750 movement, not the in-house IWC calibre 69355. The two fastest tells are the caseback engraving and the movement: genuine watches carry deep, crisp markings with a serial that matches the papers, and the 69355 shows a column wheel, a vertical clutch, and an IWC signed rotor. If the asking price sits far below the secondary market and the date sits off-center under a loupe, treat the watch as counterfeit.
What Is the IWC IW371620?
The IW371620 belongs to the Portugieser Chronograph family, a line IWC has produced in steel for decades. The reference pairs a roughly 41 mm stainless steel case with a two-register dial, a date at 3 o'clock, and a sapphire crystal treated with anti-reflective coating on both faces.
Inside sits the manufacture calibre 69355, an automatic chronograph with a column wheel and a vertical clutch. That movement is the single hardest component for counterfeiters to copy, which is why it anchors nearly every authentication check.
How Do You Tell a Fake IW371620 From a Real One?
Caseback and Engraving
Genuine IWC casebacks have laser-deep reference numbers, a serial, and the Schaffhausen hallmark with sharp edges under magnification. Fakes show shallow, rounded lettering, uneven spacing, or a serial that repeats across many listings.
Look at the caseback screws and the spacing of the engraving block. Copies often use generic screws with slightly domed heads and a wider font than IWC's own.
Dial Printing and Hands
Real dials print the IWC logo, the reference, and the Swiss Made line with clean separation between strokes. Counterfeit dials smear the smaller text, and the applied indices can sit a fraction high or low against the minute track.
Hands on a genuine watch are polished and beveled, with a blue or silver finish that changes tone as you rotate the watch. Copy hands look flat under the same light and may show tool marks at the base.
Movement and Rotor
Pull the caseback or view it through a display back if the model allows. A real 69355 has Geneva stripes, blued screws, and an oscillating weight engraved with the IWC name and the calibre number.
Replica movements are modified 7750s with printed or plated decoration, a rotor that reads slightly wrong, and chronograph pushers that feel gritty. A 7750 based fake also runs at a different beat character than the genuine column wheel movement.
Weight, Pushers, and Feel
A genuine steel Portugieser Chronograph feels dense and balanced on the wrist, with chronograph pushers that start and reset with a soft, deliberate click. Fakes run light, and the pushers often need a hard press or stick on reset.
Check the crown too. Genuine crowns carry a sharp IWC logo, while copies use a stamped mark that rubs smooth within months.
Why Are IW371620 Fakes So Common?
The Portugieser Chronograph is a simple, elegant design, and simple designs are easy to reproduce with CNC cases and printed dials. Replica factories sell the look of a five-figure watch for a few hundred dollars, so volume stays high.
The movement cannot be cloned at that price. That gap between a convincing exterior and a cheap engine is exactly where authentication lives.
What Should a Real IW371620 Cost?
New retail for a steel Portugieser Chronograph sits in the low five figures depending on strap or bracelet, and clean pre-owned examples trade below that on the secondary market. Prices move, so check current listings before you judge a deal.
A price that is a fraction of market, especially from a private seller with no service history, is the strongest single warning sign.
How Do You Verify an IW371620 Before Buying?
- Confirm the serial and reference against the warranty card and the IWC service records.
- Inspect caseback engraving depth and letter spacing under a loupe.
- Compare dial printing, index alignment, and date placement to official IWC images.
- Have a watchmaker open the case and confirm a column wheel and vertical clutch.
- Weigh the watch and compare against published specifications.
- Buy from a dealer with a return window and a written authenticity guarantee.
Can a Fake IW371620 Pass on the Wrist?
From a distance, yes, which is why photos alone are unreliable. Close inspection of the caseback, the dial text, and the movement exposes nearly every copy within minutes.
Is a Replica IW371620 Worth Buying?
A counterfeit carries no warranty, no service support, and no resale value, and it often fails within a year or two. If you want the Portugieser look at a lower cost, a legitimate alternative from a mid-tier brand holds value and can be serviced.