Quick Answer
A fake Cartier Tank Must steel is best judged by measurements, not photos. The genuine large model measures 33.7 mm by 25.5 mm with a 6.6 mm thickness. Replicas often miss thickness by 0.5 mm to 1 mm, use a flat mineral crystal instead of sapphire, and print the dial text with the wrong weight. Check the case, crown cabochon, strap, and movement before you trust any listing.
Prerequisites
- A digital caliper that reads to 0.01 mm
- A 10x jeweler loupe
- A gram scale
- Reference photos of a genuine Tank Must steel from a trusted database
Step-by-Step Evaluation
- Measure the case width, length, and thickness. Write down each number. Compare against Cartier's published specs.
- Inspect the crystal with the loupe. Look for the sapphire edge profile. A fake often shows a rounded, thick edge.
- Examine the dial printing under magnification. The word CARTIER should sit above the VI numeral with even spacing and sharp serifs.
- Check the crown. The genuine crown holds a blue synthetic spinel cabochon with a smooth dome. Fakes use glass or plastic that looks cloudy.
- Weigh the watch head without the strap. A steel Tank Must large is about 30 grams. A fake with a brass case feels lighter or heavier depending on the movement.
- Remove the case back with a case back tool. Look at the movement. Genuine quartz models use a Cartier calibre 057. Fakes often show a blank or generic Chinese quartz module.
- Inspect the strap and buckle. Genuine alligator straps have tight, irregular scales. The buckle tang should be thick and polished on all sides.
- Test the winding crown if the watch is mechanical. A fake automatic often has a gritty feel and a loose stem.
Case and Dimensions
The Tank Must steel case has a sharp, flat bezel and straight lugs. The genuine case back sits flush with the mid case. A fake often shows a gap at the case back edge or a bezel that catches light in a wavy line. The lug width on the large model is 19 mm. If a seller lists 18 mm or 20 mm, the case is not a direct copy. Measure the lug to lug distance as well. The genuine figure is 39.5 mm.
Dial, Crown, and Cabochon
Genuine Tank Must dials use a matte silver opaline finish. The Roman numerals are printed with crisp black lines. Fakes use a glossy dial or grey numerals. The crown cabochon is a blue synthetic spinel set in a steel crown. It has a deep, even blue tone. A fake cabochon looks purple or washed out under daylight. The crown itself should have fluted ridges that are cut deep and even.
Strap, Buckle, and Weight
Cartier ships the Tank Must steel on a leather strap. Genuine straps use alligator or calfskin with a soft, flexible feel. The buckle is a steel ardillon with a polished finish. Fakes use stiff leather or synthetic material. The buckle edges feel sharp. Weigh the complete watch. A genuine large model on leather is about 45 grams. A fake with a cheap quartz movement often drops below 40 grams.
Movement Check
The Tank Must steel comes in quartz and automatic versions. The quartz calibre 057 is a thin, Swiss made module. It has a smooth sweep when you set the time. A fake quartz movement ticks once per second and feels rough when you pull the crown. Automatic fakes often use a low grade clone with a noisy rotor. The rotor spins with a loud whir. A genuine Cartier automatic rotor moves with a soft, damped sound.
Red Flags
- Case thickness over 7 mm
- Cabochon that is flat or purple
- Dial text that sits too close to the VI numeral
- Strap that smells like plastic
- Movement that ticks loudly in a quiet room
Final Note
No single check proves a fake. Combine case measurements, dial print, crown details, strap quality, and movement type. If a seller refuses to share case back photos or movement photos, walk away. Use a caliper and a loupe. Trust numbers over marketing claims.