What a fake IW371645 actually is
A fake IW371645 is an unauthorized copy of the IWC Portugieser Chronograph reference IW371645, built to imitate the original without being made or approved by IWC Schaffhausen. It typically pairs a steel-style case and printed dial that mimic the real proportions with a third-party or cloned chronograph movement, and it sells for a small fraction of the genuine price.
The reference sits in the Portugieser Chronograph family, a line defined by a clean bicompax dial with two subdials, thin leaf hands, and a slim bezel that leaves most of the dial visible. Because that design is simple and highly recognizable, it is one of the easier models for a replica workshop to copy at a glance, and one of the harder ones to copy properly under a loupe.
Why this reference gets copied
Replica producers pick references based on demand, not difficulty. The Portugieser Chronograph is a well-known luxury watch with a classic layout, which means a convincing copy has a ready audience. The dial is relatively uncluttered, so the printing is cheap to reproduce. The case is a straightforward round shape, so a CNC-machined copy can look close in photos.
The hard parts are the ones that rarely get copied well: the exact curvature of the lugs, the finishing on the case flanks, the crispness of the applied numerals and indices, and a chronograph movement that starts, stops, and resets the way the original does.
How to tell a fake IW371645 from the original
Case and proportions
- Genuine cases are machined to tight tolerances, with lugs that curve to meet the wrist and brushing that runs in one consistent direction.
- Replicas often feel slightly thicker or heavier, and lug edges can be sharp rather than softened.
- Pusher action on a real chronograph is crisp with a defined click. Mushy or wobbly pushers are a warning sign.
Dial and printing
- Look at the subdials under magnification. Genuine subdial rings are cut and finished; on fakes they are often stamped or printed and can look flat.
- The brand lettering should be sharp and evenly spaced. On copies, letters may be slightly thick, uneven, or sit too close to the indices.
- Applied numerals and indices should sit level and reflect light cleanly, with no glue residue at the base.
- Hands should be flat and well finished, with no burrs at the tips and no paint spill on the leaf-shaped surfaces.
Movement and chronograph behavior
Current-production Portugieser Chronographs use IWC's own chronograph calibre, while older versions were based on a modified Valjoux 7750 architecture. Copies usually run a generic Asian chronograph movement or a clone of the 7750. Ask to see the movement through the caseback: finishing, engraving quality, and the shape of the bridges are quick tells. On the wrist, check that the chronograph seconds hand resets exactly to twelve every time and that the minute counter advances correctly.
Caseback, engraving, and paperwork
- Reference and serial engravings on genuine watches are laser-sharp and consistent in depth. Fakes often show shallow, uneven, or double-struck characters.
- Box, booklet, and warranty card quality varies widely on copies, and mismatched serial numbers between the case and the papers are common.
- Any seller who cannot show a clear macro photo of the caseback is worth walking away from.
What first copy tiers mean in practice
Sellers use terms like first copy, mirror copy, and AAA to describe quality bands, but these labels are marketing, not standards. In practice they describe three rough levels: budget copies with printed dial detail and basic quartz or low-grade mechanical movements, mid-tier copies with generic automatic chronographs, and top-tier copies that attempt to match case finishing and use cloned movements. None of them are the original watch, and the labeling tells you nothing verifiable about the parts inside.
Questions to ask before buying any copy
- Which movement is inside, and can you show a photo of the caseback and movement?
- What are the exact case diameter, thickness, and lug width?
- Is the crystal sapphire or mineral, and is it coated on one side or both?
- What is the return policy if the chronograph does not reset to zero?
- Who services the watch if the movement stops, and what does that cost?
Legal and practical reality in the US
Counterfeit goods bearing a protected trademark are subject to seizure at the border and to enforcement action against sellers, so buying or reselling a fake IW371645 carries real risk. Beyond legality, there is the practical side: replica chronographs are difficult to service, parts are not standardized, and water resistance claims are frequently optimistic. If the watch will see water, treat any unverified resistance rating as zero.
The short version
A fake IW371645 can look convincing in a thumbnail and falls apart under close inspection. Check the dial printing, the pusher feel, the chronograph reset, and the caseback engraving, and ask for movement photos before any money changes hands.