Quick answer

The reference IW371462 belongs to the IWC Portugieser Chronograph 3714 family. Counterfeits of this line are common. A fake fails on four checks: case thickness, dial printing, subdial position, and the movement behind the caseback. Published family specs list a 40.9 mm steel case, about 12.3 mm thick, 30 m water resistance, and IWC calibre 79350 at 28,800 vph. Start with thickness. Copies run thick.

Family specs to check

• Case: stainless steel, 40.9 mm diameter, about 12.3 mm thick.
• Water resistance: 30 m. Pushers are not screw-down.
• Movement: IWC calibre 79350, base Valjoux 7750, 28,800 vph, about 44 hours of power reserve.
• Dial: two subdials. Chronograph minutes at 12, running seconds at 6.
• Date: aperture at 3 on most examples.
• Crystal: sapphire with anti-reflective coating.
• Lug width: 20 mm.

IWC did not publish every variant detail for the full production run. Match the reference number against the maker's own list before you judge a single watch.

1. Measure the case

Genuine 3714 cases measure 40.9 mm across, crown excluded. Copies land at 41.5 mm to 43 mm. Thickness is the stronger tell. Genuine examples sit near 12.3 mm. Replica cases measure 13.5 mm or more, because the movement inside is a stock 7750 or a copy of it. Use calipers, not a ruler, and measure at the caseback edge.

2. Read the dial

Print quality is the second check. Genuine dials carry "IWC" and "SCHAFFHAUSEN" in sharp type. Fake dials show thick strokes, uneven letter spacing, and ink that bleeds at the corners of letters. Applied numerals on steel models have polished facets. Copies use stamped parts with soft edges and a dull finish.

Look at the subdial hands. Genuine hands reach the printed track. Copies run short or sit at the wrong angle.

3. Check the subdial layout

The base Valjoux 7750 puts running seconds at 9 o'clock. IWC reworked the calibre to move running seconds to 6. A watch with seconds at 9 is not a 79350. A watch with seconds at 6 still needs chronograph minutes at 12 and the date at 3. Wrong positions point to a different movement or a re-labeled dial.

4. Caseback and rotor

Caseback style changed over the production run. Some examples use a solid steel back. Others use a sapphire display back. Match the back to the reference and year. Engraved text on a genuine back is deep, even, and centered. Laser etching on copies looks shallow and gray.

On display-back examples the rotor carries IWC engraving and a finished surface. Copies show a plain rotor, wrong screws, or a plate without the IWC signature.

5. Serial, crown, and papers

• Serial numbers sit on the caseback and match the paperwork. Engraving depth should match the reference text.
• The crown carries the IWC mark, cut clean, not stamped.
• Boxes, warranty cards, and manuals exist for this line. Missing papers are common on genuine and fake watches, so paperwork alone proves nothing.

6. Price math

Pre-owned 3714 chronographs list in the thousands of US dollars on the secondary market. A seller asking a few hundred dollars for a steel Portugieser Chronograph is not selling a genuine watch. Ask for the reference number, a movement photo, and the case measurement before payment.

What a photo check cannot do

Photos hide thickness, weight, and finishing. A jeweler with a caseback tool can open the watch and read the movement in minutes. At this price level an authentication fee is cheap insurance.