Short answer
A fake IW329113 is a watch carrying IWC reference IW329113 that IWC did not make. Two versions exist. One is a full copy built in a replica workshop. The other is a genuine IWC watch with a replaced dial, caseback, or movement. Both fail the same four checks: caseback engraving, movement caliber, serial number record, and dial printing.
What the reference number means
IWC reference numbers use the format IW plus six digits. The digits point to a model family and a variant. IWC assigns one set of specs to each reference: case diameter, case metal, movement caliber, power reserve, water resistance, crystal, and strap. Two watches with the same reference number should measure the same at the factory gate. If a seller shows an IW329113 that is 1 mm wider, 1 mm thicker, or fitted with a different caliber than IWC lists, the case or the movement was swapped.
Public spec sheets for older IWC references are thin. IWC's own site and catalog cover current production. For a discontinued reference, ask an IWC boutique or an authorized service center for the technical data.
Caseback and engraving
IWC stamps the reference number and the serial number on the caseback. On genuine pieces the letters and digits have even depth and sharp inner edges. Replica engraving is shallow, laser cut, or ringed by a rough halo of displaced metal. Inspect it with a 10x loupe under angled light.
Serial and reference are two different numbers. The reference starts with IW. The serial is numeric, 6 to 8 digits on modern pieces. Both should match the warranty card and the certificate. A caseback with a serial that does not match the card is a red flag.
Dial and hands
Check four points. Printed text: genuine IWC dial print has hard edges and no ink bleed. Lume: applied in an even layer, one color, no dust under the paint. Applied indices: level, with polished bevels and no glue at the base. Date wheel: font matches IWC's typeface and sits centered in the window. Crystal: IWC applies anti-reflective coating to the inside face. A purple or blue tint on the outside face points to a replica.
Movement
Open the caseback or ask for a movement photo. IWC fits in-house calibers to most current references. A replica hides a basic Asian automatic, often a Seagull or a Miyota copy. Tells: blurry rotor engraving, stamped stripes instead of hand-applied Geneva stripes, painted blue screws instead of heat-blued steel, and a jewel count that does not match IWC's spec. Check the beat rate with a timegrapher. IWC calibers run at 28,800 vph (4 Hz) or 21,600 vph (3 Hz), depending on the caliber. Confirm the number for your reference before you judge.
Case, crown, and bracelet
Measure the case with calipers. Replica cases run 0.2 to 0.5 mm thicker than the original to fit a generic movement. Check the lug bevels, the brushing direction on the case flanks, and the crown logo engraving. The crown should thread in with light pressure and no wobble. Bracelet end links should sit flush with the lugs with no gap.
Price and paperwork
A stainless steel IWC runs into the thousands of US dollars at retail. A replica sells for USD 200 to 600. A price under USD 1,000 for an IW329113 with no box, no card, and no service history is a warning sign. Ask for the original invoice, the warranty card with matching reference and serial, and any service paperwork. Call an IWC service center to confirm the serial against their records.
Checklist
- Write down the IWC spec for IW329113: diameter, thickness, caliber, water resistance.
- Measure the case with calipers and compare.
- Inspect caseback engraving at 10x under angled light.
- Match serial and reference on the caseback, card, and certificate.
- Check dial print, lume, indices, and date alignment.
- Look at the crystal coating: inside face, not outside.
- Photograph the movement and match the caliber number.
- Compare the asking price against IWC retail and used market listings.
What we could not verify
We did not find a public IWC spec sheet for reference IW329113 at the time of writing. Confirm the case size, caliber, and water resistance with IWC before you compare a watch against those numbers.