Answer
Three checks catch most fake Cartier Tank Must Small watches: case thickness, crystal material, and case back engraving. A real Tank Must Small measures 29.5 mm across, 22 mm top to bottom, and 6.6 mm thick. Copies often run 1 mm to 2 mm thicker because the case holds a generic quartz movement in a plastic spacer. The real crystal is sapphire. Copies use mineral glass that hazes at an angle. The real case back carries a reference number and a serial number cut into the steel. Copies print those numbers or put them on a sticker.
Real Tank Must Small specs
- Case: stainless steel, 29.5 x 22 mm, 6.6 mm thick
- Movement: Cartier high autonomy quartz, battery life up to 8 years
- Crystal: sapphire
- Water resistance: 3 bar, equal to 30 m
- Dial: silvered opaline, or lacquer in blue, red, or green
- Strap: calfskin leather, or a steel bracelet on some references
- Retail price: about $3,000 to $3,500 US for steel on leather, and it moves with yearly price increases
Cartier launched the Tank Must in 2021 and replaced the Tank Solo line. The SolarBeat version runs on a photovoltaic cell behind the dial and uses a strap made in part from apple waste. SolarBeat models have no date and no seconds hand.
Case and crown
The crown on a steel Tank Must has a fluted edge and a blue cabochon. Cartier fits a synthetic spinel on steel models. Copies use glass or plastic. The fake stone reads flat, sits a shade lighter, and often sits on a smooth crown with no flutes.
Measure the case with calipers before you trust a listing. Case thickness is the fastest number to check, and most sellers can send a photo of the watch on a caliper jaw.
Dial and hands
The dial carries Roman numerals, a chemin de fer minute track, and sword hands in blued steel. Print on the real dial stays sharp under a 10x loupe. Print on a fake dial bleeds at the edges and sits thick on the surface.
Hands on many copies run short, so the tip stops before the minute track. Cartier hides the word Cartier inside a Roman numeral on some dials. On the Tank Must it sits in the VII. A copy with a blurred or missing secret signature is a copy.
Case back and paperwork
Four screws hold the case back. Real screws sit flush with the metal and show clean slots. Copies show chewed slots, uneven gaps, and softer engraving.
Engraving depth is the second tell. Cartier cuts the reference, the serial, Swiss Made, and 3 bar (30 m) into the steel. Copies etch the same text with a laser, so it reads gray and shallow. The serial links to the warranty card and to Cartier client records. Ask a boutique or a watchmaker to check the number before you pay. Counterfeit sets ship with copied boxes and cards. Papers raise the resale price. They do not prove the watch.
Price floors
A steel Tank Must Small on leather retails near $3,200 US. Used examples sell below retail and hold value. A listing at $400 is a fake. A listing at $1,200 is a fake, a stolen watch, or a watch with a swapped dial. No seller cuts 70% off a current model.
Before you buy
- Ask for a photo of the case back with the serial visible.
- Ask for a caliper photo of the case thickness.
- Meet a watchmaker and open the case back.
- Check the serial with Cartier client service.
- Pay with a method that allows a chargeback.