Short answer
IWC's published data for the current Ingenieur Automatic lists two case sizes: 40 mm (ref. IW3289) and 35 mm (ref. IW3249). No current IWC reference is sold as a 37 mm Ingenieur. A listing that says "Ingenieur 37" uses a size the brand does not print on a caseback. Treat that label as the first check.
Ingenieur 37 Replica Guide: Quality Checks and Prices
Reference number and serial
Every IWC caseback has a reference number and a case serial. The reference begins with IW followed by four digits, such as IW3289 for the Ingenieur Automatic 40. Compare the caseback with the dial, the hands, and the measured case width. Fake sellers pair parts from different models. A caseback for a 40 mm watch on a 37 mm case is a mismatch. IWC's service center can confirm a case serial. Ask for the serial and call before you pay.
Ingenieur 37 Copy Guide: Size, Movement and Quality Checks
Case, bezel, and bracelet
- Measure the case with calipers. IWC prints the diameter on the product page. A 2 mm gap is a flag.
- Look at the bracelet links and the clasp. On a genuine steel bracelet the links sit flush, the edges are chamfered, and the clasp engraving has depth.
- Check the crown and the tube threads. A counterfeit crown turns with grit.
Dial, crystal, and caseback
- Compare the dial text with an IWC photo at the same angle. Font weight, spacing, and the IWC Schaffhausen signature shift on copies.
- Look at the date wheel. A fake date disc sits off center and the font is thin.
- Look at the sapphire crystal at an angle. IWC crystals carry an antireflective coating that shows a faint blue tint.
- If the watch has a display caseback, inspect the rotor, the bridges, and the jewels. Counterfeit movements show tool marks and no shock spring on the balance.
Movement and caliber
IWC lists the caliber on every product page. The Ingenieur Automatic 40 uses calibre 32111. A seller who cannot name the caliber, or names a generic ETA or Miyota, is not selling an IWC.
Papers, price, and seller
Ask for the warranty card, the booklet, and the invoice. The serial on the card has to match the caseback. A steel Ingenieur Automatic 40 retails in the five-figure USD range. Listings at $300 to $900 do not reflect a discount on a current IWC. Customs agencies seize counterfeit watches each year by the thousand, and a seizure ends with a destroyed watch and no refund.