Short answer
The IW371422 sits in the IWC Portugieser Chronograph 3714 family: a 40.9 mm two-register chronograph with leaf hands, applied numerals, and a modified Valjoux 7750 inside (calibre 79350). Most fakes fail in three places: the dial printing, the case finishing, and the movement under the display back. Check those first, then move to the paperwork. Confirm the exact case metal, dial color, and strap for your specific variant against IWC reference data before you judge any single detail.
What you need before you start
- A 10x loupe
- Digital calipers
- A gram scale
- Side lighting and a dark cloth
- Reference photos of the exact IW371422 variant
Inspection steps
- Measure the case with calipers. A 3714 measures 40.9 mm across and roughly 12.3 mm thick. Many fakes run 41.5 mm or thicker because the case is cut around a stock movement.
- Weigh the watch. Compare the result against a known example in the same metal and strap. Solid gold cases carry obvious heft; a plated fake feels light for its size.
- Read the dial under the loupe. Lettering should be sharp with no ink bleed, even stroke weight, and correct spacing between the printed lines. Look for thick serif fonts, fuzzy edges, and lume that sits proud of the dial.
- Check the register layout. Chronograph minutes sit at 12 and running seconds at 6. Rings should be perfectly centered and level with the dial surface.
- Study the hands. Leaf hands are flat, polished, and slightly curved along their length. Fakes use thicker, flatter hands with rough edges at the tip.
- Inspect the case finishing. Brushed surfaces run in one direction, polished bevels are crisp, and the lug edges are sharp without burrs. Run a fingernail along the lug flanks.
- Check the crown and pushers. The crown is signed and sits flush; pushers should have short, firm travel with a clean click. Mushy pushers point to a cheap chronograph module.
- Look at the crystal at an angle. Sapphire with coating on both sides shows almost no reflection. A blue or purple flare usually means mineral glass or single-sided coating.
- Examine the caseback engraving. Factory engraving is deep and even. Laser etching on fakes is shallow and washes out under raking light. Compare the reference and serial between the lugs with the paperwork.
- Open the display back and look at the movement. Expect clean finishing, polished screw heads, correct rotor engraving, and a balance oscillating at 28,800 vph, which is 8 beats per second.
- Run the chronograph. Start, stop, and reset should snap back to zero in one motion. Sluggish reset or a drifting hand is a common fake symptom.
- Listen to the rotor. A light, tight wind is normal. A rattling or scraping sound means a low-grade movement.
Paperwork and seller checks
- Match the serial on the watch to the warranty card and the dealer stamp date.
- Compare the asking price with current secondary-market listings. A price far below market for the reference is the single strongest signal.
- Ask for macro photos of the dial, caseback, and movement before any payment.
- Prefer sellers who accept returns and offer escrow or a verified payment path.
Red flags that end the deal
- Serial numbers that do not match across watch, card, and box
- Photos that are low resolution or borrowed from a catalog
- Pressure to pay outside a protected channel
- A seller who cannot name the calibre or the case size