A fake IW371717 is a copy of the IWC Pilot's Watch Chronograph from the 3717 family, and the details that expose most of them are dull ones: the day and date wheel, the thickness of the case, the print on the dial, and the movement behind the solid back. I check those four before I look at anything else, because they are the hardest things for a replica factory to get right and the easiest things for a buyer to inspect in ten minutes.
If you only remember one thing, remember this: the reference number on the caseback has to match a real IWC variant, and the day-date window has to look correct under a loupe. Everything else is secondary.
What the IW3717 reference actually is
The 3717 is IWC's Pilot's Watch Chronograph sold from roughly 2006 to 2012. Steel case, 42mm across, day and date at 3 o'clock, chronograph registers driven by the same architecture as the Valjoux 7750, and IWC's own calibre 79320 inside. It runs at 28,800 vibrations per hour with about 44 hours of reserve. Water resistance is rated at 60 meters, and the crystal is sapphire with anti-reflective coating on both faces.
Two spec details matter more than people expect. First, the case is about 14.5mm thick, because IWC fitted a soft-iron inner cage for anti-magnetic protection. Second, the caseback is solid. There is no display back on a 3717. If a seller shows you an open caseback on a watch claimed to be this reference, either the back has been swapped or the watch is not what it claims to be.
The 3717 line covers several variants that differ by dial color, hands, and bracelet or strap. IW371717 sits inside that family. Because sellers quote reference numbers loosely, the honest move is to check the number against a proper reference database and confirm the dial and bracelet combination actually exists.
Why this reference gets copied so heavily
The movement is the main reason. The 7750 layout is well understood, and Chinese-made copies of it have been around for decades, so a factory can build a working chronograph without inventing anything. The dial is also busy, which is useful for a counterfeiter: subdials, numerals, and text give the eye plenty to look at and plenty of places for sloppy work to hide.
Steel pilot cases are simple to machine, too. There is no complicated precious-metal finishing to fake, no guilloche, no enamel. That is why the fakes scale.
The checks that catch most fakes
- Day and date wheel. On a genuine 79320, the day and date sit level, centered, and in the correct font weight. Fakes tend to sit low in the window, use a thinner font, or print the day wheel in the wrong language order.
- Dial print. Look at the IWC logo and the SCHAFFHAUSEN line. Genuine print is crisp with even letter spacing. On replicas the letters often crowd together or the serifs soften.
- Case thickness. A thin 3717 is a warning sign. Replica makers skip the soft-iron cage, and that cage is part of why the real watch is chunky.
- Caseback engraving. Deep, sharp engraving with a legible reference number. Shallow laser etching that fades at an angle is common on copies.
- Crown and pushers. The crown should thread smoothly and pull to clear positions. Pushers should start and stop the chronograph with a firm click, and reset should snap back to zero in one motion.
- Crystal and coating. Genuine double AR coating gives a slightly blue or purple sheen at certain angles. A single-side or missing coating shows up as flat glare.
- Bracelet and clasp. Check the clasp engraving and the fit of the links. Loose end links and shallow stamping are typical of lower-tier copies.
The movement is the part you cannot see
Since the back is solid, movement quality only shows up in behavior. Wind the crown and feel for grit. Run the chronograph and watch the seconds hand sweep: it should move in small, smooth steps, not tick. Start the chronograph and check that the minute counter advances exactly when the seconds hand passes twelve.
An A7750-based copy can run well for years, but it is not a 79320. The finishing, the rotor engraving, and the regulation are different, and the service network is different. If a seller will not open the watch or provide a clear movement photo, treat that as a no.
Tiers of fakes, and what each one means
There are roughly four levels. Quartz junk with a sweeping seconds hand that stutters is the bottom. Basic automatics with a low-beat movement come next. Then the A7750 tier, which is where most convincing copies live. At the top are gen-spec builds that use a genuine-spec case and dial with an aftermarket movement. None of them include the soft-iron cage, and none of them should be sold to you as genuine. Selling a replica as a real watch is fraud in most countries, including the United States.
Questions worth asking before you pay
- What is the measured case thickness, in millimeters?
- What movement is inside, and can you show a photo of the rotor?
- What reference number is engraved on the caseback, and which dial variant is it?
- Does the day wheel show the language set you expect?
- Is the price consistent with the current secondary market for a real 3717, or far below it?
That last question solves a lot of cases on its own. A genuine 3717 trades in the low thousands of dollars on the used market. A four-figure discount with a story attached is usually not a bargain.
Bottom line
A fake IW371717 is not hard to catch once you know where to look. Start with the day-date window and the case thickness, then move to the print, the caseback, and the feel of the chronograph. If any one of those is off, stop. There are plenty of real 3717s out there, and paying a fair price for one beats paying a fake price for a watch you will second-guess every time you put it on.