A fake IW371648 is a counterfeit copy of the IWC Portugieser Chronograph, and the fastest way to identify one is to compare four things against a genuine example: the spacing of the two sub-dials, the sharpness of the dial printing, the depth of the caseback engraving, and the beat rate of the movement. Copies that fail those checks are usually obvious within a minute of handling.
What the IW371648 Actually Is
The IW371648 belongs to the Portugieser Chronograph family, a line IWC has built across several generations. Case size, dial layout, and movement changed between generations, so confirm the exact specification for your reference and production year on IWC's own reference pages before you judge any single watch. A seller who cannot state the calibre, case diameter, and water resistance for the watch in hand is already a warning sign.
Dial and Printing Checks
- Sub-dial alignment. The chronograph uses two registers on a vertical axis. On a fake, they often sit slightly off-center, sit too close to the printed model text, or show uneven gaps to the minute track.
- Text sharpness. Genuine dial printing is crisp with no bleeding at the edges. Look at the brand name and the model line above six o'clock under a loupe or a phone macro shot.
- Applied numerals. The metal numerals and markers should sit flat with even polishing and no glue residue around the base.
- Hands and finish. Leaf-shaped hands should be cleanly finished with no burrs, and the chronograph seconds hand should sit exactly at zero when reset.
- Minute track. The printed track should be uniform in thickness the whole way around, with no faded or joined ticks.
Case, Pushers, and Crown
Check how the chronograph pushers feel. Genuine pushers have a short, clean travel with a positive click; cheap copies feel mushy or grind at the end of the stroke. The crown should wind smoothly with no wobble in the stem. On the case, look at the transition between brushed and polished surfaces. Fakes often blur that line, leave polishing marks in the wrong direction, or round off edges that should be sharp.
Caseback and Engraving
Reference numbers, serial numbers, and the surrounding text should be cut deeply and evenly. Laser-etched fakes look grey and shallow under raking light, and the font is frequently slightly wrong in spacing or weight. On display-back models, examine the rotor and bridges for finishing quality and for the engraving IWC applies to its in-house movements. Cross-check any reference or serial you can read against the seller's description and paperwork.
Movement Tells
If you can see the movement or watch the seconds hand, judge the sweep. A genuine mechanical chronograph should show a smooth advance; a stutter, a jumpy chronograph seconds hand, or a balance ticking well below the expected rate points to a substitute movement. Ask for a timed rate reading or a service receipt. Any watch sold without service history should be priced and treated accordingly.
Weight, Feel, and Bracelet
A steel Portugieser Chronograph has a solid, dense feel on the wrist that light copies rarely match. Check the end-link fit against the case, the crispness of the clasp engraving, and whether the bracelet pins are properly finished. Loose end links, a rattling clasp, or a hollow-sounding case are all reasons to walk away.
Premium Replica vs Counterfeit Sold as Genuine
These are different problems. A replica openly sold as a replica is one product category; a counterfeit passed off as an authentic watch is fraud, and it is illegal to sell one that way in most markets. When a listing claims a fake IW371648 is genuine, the price, the paperwork, and the seller's willingness to meet a watchmaker for inspection are your best filters before money changes hands.
Pre-Purchase Checklist
- Ask for macro photos of the dial, caseback, clasp, and movement.
- Confirm the reference and serial against IWC's published information.
- Request a movement timing reading or a recent service invoice.
- Meet at an independent watchmaker for an inspection before payment.
- Pay with a method that offers buyer protection, never by wire to a stranger.