The replica IW371646 is a copy of the IWC Portugieser Chronograph in stainless steel with a blue dial, a 41 mm case and a twin-register chronograph layout. A good copy gets the dial symmetry, sub-dial spacing and slim bezel right; a weak one misses on case thickness, hand length and sub-dial finish. Use those three points as your first filter when you compare sellers.
What the IW371646 reference actually is
IW371646 sits inside the current Portugieser Chronograph family, the line IWC refreshed with an in-house chronograph movement and a cleaner dial. The defining traits are a round steel case of about 41 mm, a narrow bezel that leaves a large dial opening, applied numerals at 12 and 6, and two recessed counters instead of three. The blue dial version is the one most often copied, because a sunburst or lacquered blue surface shows finishing flaws fast, which makes it a useful reference point for judging quality.
Key specifications to compare
- Case size: roughly 41 mm across and about 13 mm thick on the original, so a replica that measures 14 mm or more will sit visibly taller on the wrist.
- Dial layout: running seconds at 6 and a 30-minute chronograph totalizer at 12, with the date window at 3.
- Movement: the genuine watch uses a column-wheel chronograph calibre with a roughly 46-hour power reserve.
- Crystal and back: domed sapphire with anti-reflective coating, sapphire display back on the steel version.
- Water resistance: rated to 30 m on the original, which is splash resistance rather than swimming depth.
Dial details that separate good from poor
The dial is where most replica Portugieser chronographs fail. Look for crisp, raised printing on the minute track, numerals that are applied rather than painted, and sub-dials that sit at the correct depth with a fine circular graining. The hands should be long enough to reach the minute track at every position, with a slim leaf shape and a clean bend toward the crystal. On blue dials, check that the color holds steady in daylight instead of shifting toward purple, and that the date wheel sits flush and centered in its cutout.
Case finishing and proportions
A Portugieser case lives on its brushing and polishing. The lugs should carry a straight, even satin grain with polished flanks that meet at a defined edge, not a rounded blur. Thin lugs and a slim bezel are the hard parts to copy, so a replica that looks chunky in photos usually looks worse in person. Ask for measurements and side-profile photos before you buy.
Movement choices in replica chronographs
Most replica chronographs in this size use either a modified Asian Valjoux-type movement or a clone of a modern column-wheel design. The Valjoux-type option is proven and easy to service, but it usually adds height and can make the sub-dial positions slightly different. Column-wheel clones offer a smoother pusher feel and a thinner profile, at a higher price and with fewer watchmakers willing to touch them. Confirm which movement is fitted, whether the chronograph resets cleanly to zero, and whether the seconds hand sweeps without stutter.
Questions to ask a seller
- Exact case diameter and thickness, measured rather than quoted from a listing.
- Photos of the movement through the display back, plus a short video of the chronograph starting, stopping and resetting.
- Strap type and whether the buckle is signed, since hardware is often the weakest part.
- Return policy and warranty terms in writing, including who pays shipping on a return.
Setting expectations
A replica IW371646 can look convincing on the wrist, but it is not the original and will not hold value or carry the same service support. Treat it as a fashion purchase with a limited lifespan, budget for a service or replacement within a few years, and avoid any seller who promises genuine parts or certified authenticity. Buy from a seller who answers technical questions directly, shows real photos of the actual watch, and keeps the transaction simple.