A fake IW371752 is a replica of the IWC Pilot's Watch Chronograph from the ref. 3717 family, and the fastest way to identify one is to inspect the movement and the calendar window. The genuine watch runs IWC caliber 79320 with a day-date at 3 o'clock and subdials at 12, 6, and 9. Most replicas hide a generic Asian chronograph movement, so the font, the subdial spacing, and the caseback engraving rarely match the real reference.
What Is the IW371752?
IW371752 is a reference code inside IWC's Pilot's Watch Chronograph 3717 line, a 42 mm stainless steel automatic chronograph. Suffix numbers in that family generally describe dial color and bracelet combination, so the 752 variant is a specific steel configuration rather than a separate model.
The specification includes a soft-iron inner case for magnetic shielding, sapphire crystal with anti-reflective coating on both sides, a screw-down crown, and water resistance rated to 6 bar. Genuine examples use caliber 79320, a Valjoux 7750 base that beats at 28,800 vibrations per hour with a 44-hour power reserve.
How Do You Spot a Fake IW371752?
Replica makers copy the silhouette well and the details poorly. Work through these points in order, starting with the dial and finishing with the movement.
- Case size and thickness. Genuine 3717 watches measure 42 mm across and about 14.5 mm thick. Many fakes run 43 to 44 mm and sit noticeably taller, which throws off the lug-to-lug balance on the wrist.
- Day-date at 3 o'clock. The real calendar uses a stepped, tightly spaced font with clean apertures. Cheap copies show a flat printed font, fuzzy edges, or a date disc that sits off-center.
- Subdial layout. Counters belong at 12, 6, and 9, with running seconds at 9. A ticking seconds hand at 9 that jumps once per second means quartz, not mechanical.
- Dial printing. Look at the IWC wordmark and the Schaffhausen line. Genuine text is razor sharp under a loupe. Replica text is thicker and often uneven in weight.
- Crystal coating. Genuine sapphire shows a faint blue or purple tint from the anti-reflective coating on both faces. Many fakes coat only the outside or skip it.
- Caseback engraving. Reference and serial numbers are cut deep with crisp edges on the real watch. Laser-etched fakes look shallow and washed out.
- Crown and pushers. The crown should screw down smoothly and the pushers should give a firm click with a snap-back reset.
Why Is the Movement the Hardest Part to Copy?
The 79320 is a modular chronograph built on the Valjoux 7750 architecture, and that architecture leaves visible fingerprints. A genuine example shows a rotor that winds with a slight wobble, a chronograph engagement that feels mechanical rather than mushy, and a seconds hand that sweeps in eight small steps per second.
Replica builders usually fit an Asian 7750 copy or a quartz module. The Asian copy can look convincing on a bench, but the pusher feel, the reset snap, and the timegrapher readings rarely match. Any watch whose seconds hand ticks once per second is not running the original caliber.
Which Replica Grades Exist for This Reference?
Fakes of this model fall into three rough tiers. Budget copies use quartz movements, printed dials, and base metal cases. Mid-tier copies use an Asian 7750 clone with a copied date wheel, and they often get the case dimensions close while missing the dial texture.
The top tier advertises itself as a Swiss super clone or a 1:1 replica. Even there, the calendar font, the crown threads, and the caseback stamping tend to give the watch away under magnification.
Does the Serial Number Prove Authenticity?
No. Replica factories engrave plausible serial numbers on the caseback, and some reuse a single number across a production run. A serial only helps when you verify it against IWC service records or compare it with documentation from an authorized dealer.
What Should You Ask a Seller For?
Request photos of the caseback, the crown-side profile, a macro shot of the date window, and a clear movement image with the caseback removed. Ask for a timegrapher reading showing rate, amplitude, and beat error.
Legitimate sellers of a genuine 3717 chronograph supply these without hesitation. A seller who avoids movement photos, refuses a video call, or prices the watch far below the secondary market is signaling a problem.
Quick Authentication Checklist
- Confirm 42 mm case width and roughly 14.5 mm thickness.
- Verify the day-date sits at 3 o'clock with a stepped font.
- Check subdials at 12, 6, and 9 with running seconds at 9.
- Watch the seconds hand sweep in eight steps per second.
- Inspect caseback engraving depth and font consistency.
- Compare the asking price with current secondary market listings.