Short answer
A 40mm Speedmaster selling for a few hundred dollars is a counterfeit. Genuine 40mm Speedmasters, including the Speedmaster Racing and several automatic Speedmaster Date references from the 1990s and 2000s, trade in the four figures and up. Copies slip through because those older 40mm references are photographed far less than the 42mm Moonwatch Professional, so sellers post soft images and count on buyers never measuring the case. The checks below take about ten minutes.
Which Speedmasters are really 40mm
- Moonwatch Professional: 42mm, the reference most people picture.
- Speedmaster Racing: 40mm, chronograph with a date window.
- Speedmaster Date and automatic models from the 1990s and 2000s: 39mm to 40mm, depending on reference.
- Speedmaster Reduced: 38mm to 39mm, often listed as 40mm by error or on purpose.
What you need before you inspect
- A digital caliper.
- A 10x loupe.
- Photos of the genuine reference from a published reference guide.
- The seller's return policy in writing.
Step by step checks
- Measure the case across the bezel at the 3 and 9 o'clock positions, crown excluded. A real 40mm Speedmaster lands between 40.0mm and 40.5mm. Copies often come in at 41mm or 39mm because the case was copied from a different reference.
- Measure thickness across the crystal and caseback. Genuine 40mm Speedmasters sit near 12mm to 13mm. Many copies measure 14mm or more and ride high on the wrist.
- Read the reference number on the caseback and match it to the dial layout. If the number points to a Moonwatch Professional but the watch has a date window, the caseback does not belong to that watch.
- Study the caseback engraving under the loupe. Genuine text has crisp, even strokes. Copies show rounded edges, uneven depth, and misaligned characters.
- Check the dial printing. The word Speedmaster should sit level and centered, with clean serifs. Copy dials crowd the text against a subdial or use heavier strokes.
- Inspect the subdials. On a three register chronograph the subdial centers should align on one horizontal line. Copies sit a fraction of a millimeter off.
- Look at the date window. It should be square, chamfered, and centered in its aperture. Copies show a gap on one side or a crooked date wheel.
- Check the hands. The chronograph seconds hand should reach the minute track, and the hour and minute hands should not touch when stacked.
- Work the chronograph. Start, stop, and reset it three times. Genuine pushers have short, firm travel and the reset snaps the hand back to zero. Copies feel mushy and the hand stops two seconds off zero.
- Examine the bracelet end links. They should meet the lugs with no gap and no rattle. Copy end links leave a visible seam, and the clasp stamping is shallow.
- If the watch has a display back, study the rotor text and movement finish. Copy rotors use flat engraving and the movement screws are unpolished.
- Ask for the warranty card, pictograms card, and box. Compare the serial on the card with the serial on the caseback. A mismatch means a parts watch, a fake, or stolen property.
- Have a watchmaker open the case and confirm the movement caliber before you pay. This is the one check no photograph can fake.
Why the 40mm size trips people up
Most counterfeit Speedmasters are built around the Moonwatch profile because that is the shape buyers recognize. When a listing says 40mm, the seller is describing an older automatic reference that is harder to verify from images. That gap is where copies live. If a listing claims 40mm, treats the watch as a Moonwatch, and never shows a reference number, walk away.
Legal note
Buying or selling counterfeit watches is illegal in the United States. Customs can seize the shipment, and trafficking in counterfeit goods exposes the seller to civil liability and criminal penalties. A counterfeit also has no factory service, no parts support, and no resale value.