The IW323760 is a specific IWC reference, not a model family name. Replicas sold under that number fail on the same points again and again: the reference string on the caseback, the case dimensions, and the movement behind the display back. Verify the reference first, then the case, then the movement.
What the reference number tells you
IWC writes references as the letters IW plus six digits. The first four digits name the family and the last two name the variant, which covers case metal, dial color, and whether the watch leaves the factory on a strap or a bracelet. Two watches can share a family name and still be different references. A seller who cannot state which variant they hold is guessing.
Before you start
- A 10x loupe or a macro lens for your phone
- A digital caliper that reads to 0.01 mm
- A kitchen scale that reads to 0.1 g
- Bright white light, not warm room light
- Photos of the genuine reference from the IWC catalog
- A watchmaker who will open a caseback for you
How to check an IW323760
- Read the caseback engraving with the loupe. Genuine IWC engraving has crisp edges and even depth. Replica engraving looks shallow, rounded, or filled with polish residue.
- Confirm the full reference string. It must read IW323760 with no missing digits, no extra spaces, and no font that mixes weights inside one line.
- Measure the case diameter at the 9 to 3 line and the thickness from crystal top to caseback. Compare both numbers with the catalog figure for that variant.
- Measure the lug width. A 0.5 mm difference rules out the genuine case.
- Weigh the head without the strap. Plated brass and thin steel cases come in light.
- Study the dial print under magnification. Genuine print sits flat with sharp shoulders. Replica print feathers at the edges and thins on curved text.
- Check the applied indices. Each one should sit level, with a polished bevel that catches light from a single direction.
- Look at the date window. The aperture edges should be cut clean and the date should sit centered with the correct font weight.
- Turn the crown through a full wind and set the hands forward and backward. Grit, wobble, or a crown that pulls out in steps points to a cheap movement.
- Inspect the crystal edge and the anti-reflective coating. Genuine coatings cut glare to a faint blue or purple. Many replicas show a heavy green cast.
- Check the bracelet screws, end links, and clasp. Genuine screws have uniform slots and thread without grit. Replica screws strip and sit proud of the link.
- Have a watchmaker open the caseback. Compare the movement finish, the rotor engraving, and the jewel count against the genuine caliber.
- Match the serial number to the reference and to the papers. Ask for a service record or a dealer invoice that shows both numbers.
Replica tells that show up most
- Rounded or double-struck engraving on the caseback
- Case thickness off by more than 0.3 mm
- Dial text that is too thick or too close to the index ring
- Green tint in the crystal coating
- Rotor that spins with a metallic scrape
- Papers printed on generic stock with a default font
What a 1:1 claim means
A 1:1 claim describes how a replica was marketed, not how it was built. Sellers use the phrase to signal a higher tier of copy, and the phrase carries no standard behind it. Judge the watch on the checks above instead of the label on the listing.
When to walk away
Walk away if the seller blocks a caseback photo, refuses a caliber photo, or quotes a reference that does not match the dial and case in the pictures. A genuine watch survives all three requests. A replica does not.