Pick first: steel case, 41 mm, true 12/6 dial layout
If you buy only one fake IW371634, make it the steel case with a silver-plated or blue dial on a leather strap, and insist on a movement built for the 12/6 subdial layout. That version is the most copied, the most photographed and the easiest to judge from seller images. Every other choice in this guide is a variation on that base: rose gold plating, alternate dial colors, boutique editions, strap swaps. Get the base right and the watch reads correctly at arm's length. Get it wrong and no dial color rescues it.
The movement decides the purchase. On the genuine Portugieser Chronograph the running seconds sit at 6 and the chronograph minutes sit at 12, both on the vertical center line. Replicas that use a stock A7750 plus a transfer module to relocate those counters finish 1.5 to 2.5 mm thicker than the real 13 mm case, and the pushers and crown sit low on the flank. That extra height shows in a side profile photo and in the way the watch tucks under a shirt cuff. A dedicated 12/6 movement, whether a clone of the 69355 or a modified layout, removes the problem at the source.
What to look for in a fake IW371634
Case and profile
- Diameter 41.0 to 41.3 mm across the bezel, crown excluded.
- Thickness 13.0 to 13.6 mm is correct. Up to 14.2 mm is tolerable only when the caseback is domed. Anything past 14.5 mm signals a module build.
- Lug width 20 mm. Ask for the measurement, because 21 mm straps turn up on cheaper builds.
- Lugs should curve down from the case with a crisp inner bevel, not run as a flat slab.
Dial
- Both subdial centers must sit on the vertical axis. On a straight-on photo the gap between the two counters should be even and the centers should line up with the 12 and 6 markers.
- Hands are leaf shaped and faceted with a slight taper. Over-polished hands look flat and lose the facet line.
- Applied numerals at 12 and 6 are thin and polished, with sharp edges.
- Printing of the wordmark, SCHAFFHAUSEN, AUTOMATIC and the minute track should stay crisp under a loupe. Soft serifs on the wordmark are a tell.
- The railway minute track needs evenly spaced hash marks and a clean inner edge.
Crystal
- Sapphire with antireflective coating on both faces. Without coating the dial reads gray in daylight.
- The edge should sit flush or just proud of the bezel. A tall, thick crystal distorts the dial at an angle.
Caseback and movement
- Match the caseback type to the reference you are copying. Solid backs hide the movement, display backs expose it. On a display back the rotor engraving, bridge finishing and balance cock all join the comparison.
- The genuine calibre 69355 is a column-wheel chronograph. Ask the seller whether the replica uses a column wheel or a cam. A seller who cannot answer is a seller to skip.
- The movement should be named. A Swiss label printed on a movement assembled in Asia is a claim, not a fact.
Strap and hardware
- The strap is the cheapest part to replace, so do not pay a premium for it. Spend the attention on the buckle engraving instead.
- A pin buckle should be brushed on top with polished flanks and a clean engraving depth.
Parameter bands worth memorizing
- Case diameter: 41.0 to 41.3 mm passes. 40.5 to 41.0 mm is marginal. Anything else fails.
- Case height: 13.0 to 13.6 mm passes. 13.6 to 14.2 mm is marginal. 14.5 mm and up fails.
- Lug width: 20 mm passes. 19 mm or 21 mm fails.
- Head weight on leather: roughly 70 to 85 g passes. A very light head points to a hollow case.
- Subdial centers: aligned to the vertical axis within 0.3 mm.
Common pitfalls
- Studio photos that hide thickness. Request a side profile shot on a flat surface next to a ruler.
- 1:1 claims with no measurements attached. Ask for caliper readings of diameter, height and lug width.
- Rose gold plating with a copper-pink tone instead of the warmer alloy of the genuine. Compare in daylight, not under a light box.
- Extra complications the reference never had. The IW3716 dial carries two subdials and no date. A date at 3 belongs to a different watch.
- Water resistance claims. The genuine is rated to 3 bar. Do not swim with either one.
- Box and papers offered as a value add. They change nothing on the wrist.
FAQ
Is the IW371634 a real reference?
The IW3716 family covers dial and case metal variations, and some of them are boutique-only. Confirm the exact dial color and case metal of the reference you want before you compare photos, because sellers mix images from several variants in one listing.
Can I judge a fake IW371634 from seller photos?
Partly. Insist on three shots: a straight-on dial photo with the watch lying flat, a side profile on a table, and a caseback close-up. Those three answer the thickness, subdial alignment and movement questions in one pass.
Fake IW371634: What Makes the Best Build Different
Should I pay more for a decorated movement?
Only when the caseback is a display back. On a solid-back build the decoration stays hidden and the money is better spent on the dial, hands and case finishing.
How close is a good replica at arm's length?
Close enough that thickness and subdial alignment are the two things people notice first. Fix those and the rest is detail work.