The short answer
The Tank Allongée is a proportions watch. Get the length-to-width ratio, the thinness, the crown cabochon, and the dial print right, and the replica reads as the real shape from across a table. Get two of those wrong and it looks off even to people who don't know Cartier. Before paying, ask the seller for a caliper photo of the case and the name of the movement. If either answer is vague, you are buying a stock photo, not a watch.
What the Allongée shape actually is
Allongée means elongated in French, and that is the whole idea: a Tank case stretched into a long, narrow rectangle with straight sides and lugs that follow the case line. It is not the Cintrée, which curves to hug the wrist, and it is not the Normale, which is closer to square. The Allongée sits in the middle of the family history, thin, hand-wound, and small on paper but long on the wrist.
That shape is also why replicas of it are hit or miss. Factories that already cut the popular Tank cases can stretch the dimensions, but the stretch changes the balance of the dial, the angle of the lugs, and how the strap falls. Most budget versions look like a squashed Tank Louis instead of an Allongée.
Case proportions and finish
- Length and width. The ratio should land near 2:1, often a bit more. A caliper shot in the QC photos is the only proof. A listing that says "large size" without numbers is telling you nothing.
- Thickness. Vintage-inspired Tanks are thin, generally under 8mm and often closer to 7. A replica that measures 9mm or more is usually hiding a thick automatic movement.
- Metal. The genuine article is solid 18k gold. Replicas are gold-plated steel, and the plating is where the money went or didn't. Ask whether it is plating or PVD, and how many microns.
- Lugs and caseback. Lugs should be soldered flush and finished on the inside, not left rough. Caseback engraving on good replicas is shallow and clean, not deep and stamped.
Dial, numerals, and hands
Cartier dials are a printing exercise. The Roman numerals should be crisp with sharp serifs, the rail-track minute ring should be even all the way around, and the word Cartier at 12 should hold up under a loupe. On many Tanks, the secret signature hides inside the VII numeral. Cheap replicas either skip it or paint a blob that falls apart at 3x magnification.
Hands are the fastest test you can run at home. Blued steel looks nearly black at most angles and flashes blue when you hit it with a phone light from the side. Painted blue hands look flat and purple at every angle. Two seconds, no tools.
The crown and cabochon
The crown should be faceted and set with a deep blue cabochon, traditionally a synthetic spinel or sapphire. Bad replicas use a smooth dome, a plastic bead, or something closer to purple than blue. Look at it under daylight, not warm indoor lighting, because warm light flatters bad stones.
Movement: what you can and can't see
Most Tank-style watches are two-hand, with no seconds hand. That means you cannot spot a quartz replica from the front. There is no ticking sweep to give it away. The tells are thickness, winding feel, and the caseback. A hand-wound clone movement feels gritty and stops hard at full wind; quartz has no crown resistance beyond a stem click.
This is also why sellers can quietly ship quartz and nobody notices for a month. Ask directly, and get it in writing in the chat log.
Strap and hardware
Genuine Tanks ship on alligator with a matching buckle or deployant. Replicas usually come with stiff embossed leather that cracks at the lugs within months. Budget for a replacement strap from day one. Check the buckle engraving depth and whether the pin lines up square with the frame. Crooked hardware is the most common giveaway on an otherwise solid replica.
What the listing won't tell you
- Plating wears through at the lug tips and caseback edges, often within a year of daily wear.
- Solid gold weighs noticeably more. If you handled a genuine once, a plated replica feels hollow.
- Nobody services these. When a clone movement dies, you replace the watch.
- Water resistance claims are marketing. Treat any replica as splash-proof at best.
The US legal picture
Customs can and does seize counterfeit watches at ports of entry, and importing or selling trademark-infringing goods is a violation that sits with the importer, not the factory. Replicas stamped with fake gold hallmarks cross into a worse category, because that is fraud about material, not just about brand. Personal-use purchases are a gray area in practice, but the risk lands on you.
A checklist before you pay
- Caliper photo of length, width, and thickness.
- Named movement, quartz or mechanical, stated in the chat.
- Macro shot of the dial at 12 and of the VII numeral.
- Side-lit photo of the crown cabochon.
- Close-up of the buckle engraving and the strap stitching.
- Confirmation of plating type and thickness.
Work through that list and you will filter out most of what is on the market. The Allongée rewards buyers who care about millimeters, because that is the only thing the watch is really about.