The Cartier Tank Must Blue is a steel quartz watch with a blue lacquered dial. Cartier added the Tank Must line in 2021 as the entry level Tank. Copies sell from about $80 to $400. Four parts decide the quality of a copy: the dial print, the case size, the crown cabochon, and the caseback text.

Specs to verify

  • Large case: 33.7 mm by 41 mm, 6.6 mm thick, per Cartier.
  • Small case: a shorter version exists. Ask the seller for measurements and compare them with Cartier data.
  • Movement: quartz. No mechanical option sits in the steel Tank Must.
  • Crystal: sapphire.
  • Water resistance: 30 m.
  • Dial: no date window.

Dial checks

The genuine dial is blue lacquer over a metal base. It reads as a flat, deep blue. Hold the watch under a lamp. A sunray finish or a metal flake finish is wrong. Roman numerals should hold even stroke width. The gap between the numerals and the minute track should match on both sides of the dial. At 10x, a copy shows broken lines and thick edges.

Hands are sword shape. The tips should touch the minute track.

Case and crown

Cartier finishes the Tank Must with a mix of polish and brush. Copies tend to polish the whole case or brush the whole case. Compare the flank and the bezel side by side.

The crown holds a blue spinel cabochon. Genuine stones sit low in the crown and hold their blue in daylight and indoor light. Copies use glass or plastic. The color shifts toward purple under LED light.

Measure the case with calipers. A copy that reads 34.5 mm wide sits 0.8 mm over the Cartier figure. Lug to lug and thickness matter in the same way.

Movement and caseback

The genuine runs on a quartz caliber. The seconds hand steps once per second. A sweeping seconds hand on a Tank Must means the watch carries a mechanical movement, which does not match the real watch.

The caseback is solid steel with engraved text: reference number, serial, and "Swiss Made." Deep, sharp engraving is a good sign. Laser etching that washes out at an angle is not. Cartier reference codes use four letters and four digits. The blue lacquer model has its own reference, separate from the silver dial steel Tank Must. Confirm the code with Cartier before you buy.

Strap and buckle

The blue model ships on a blue calfskin strap. The buckle is steel. Check for solid steel with a clean edge. Stamped sheet metal bends by hand. Stitching should be even, with the same thread color as the leather.

Price points

  • $80 to $150: mineral glass, flat printed dial, light case.
  • $250 to $400: sapphire glass, closer case profile, cleaner print.
  • Genuine: Cartier lists the steel Tank Must in the low $3,000 range in the US.

Red flags

  • Listing photos show a genuine watch.
  • Case measures 1 mm or more off the listed size.
  • Cabochon is plastic, or turns purple under LED light.
  • Dial print shows broken lines at 10x.
  • Buckle flexes by hand.
  • Seller cannot show the caseback.

Open items

Replica batches change without notice. Caseback text and dial print differ between versions. Ask for photos of the exact unit and a photo of the caseback before payment.