Answer first: the reference written as 162351 points to a Cartier Santos from the Galbée period, a compact square watch with a stepped bezel, exposed screws, a Roman numeral dial, and an integrated bracelet. Most people searching this number are looking at replica listings, and the useful question is not whether the watch is a replica but which grade of replica it is. A budget copy and a high-grade replica share only the shape. The criteria below separate them: case geometry, bezel screw execution, dial printing, crown cabochon, bracelet fit, and movement.

What the 162351 reference actually is

The number appears in marketplace listings for a Santos with the Galbée case proportions: smaller than the modern Santos, squared off, with a bezel that steps down into the case. Cartier reference numbers are not applied with total consistency by resellers, so treat the number as a starting point rather than proof. The caseback engraving, the measured case size, and the movement type are what confirm the model. If a listing pairs the number 162351 with a large modern Santos case, the listing is confused about what it is selling.

• Pros of buying by reference number: it narrows your search fast and filters out listings for unrelated models.
• Cons: numbers get copied between listings, so a wrong number spreads through a whole batch of replicas.

Use case: useful when you already know the shape you want and need to compare sellers on the same model.

Case and bezel: where replicas show their grade

The Santos is hard to copy because the design is almost entirely flat surfaces and straight lines. Any softness in the edges reads from across a room.

What a high-grade replica gets right

• Flat, satin-brushed case sides with polished bevels that stay sharp where the two finishes meet.
• Bezel screws with clean slots, even depth, and a consistent orientation around the bezel.
• A bracelet-to-case junction that sits flush, with no step, lip, or gap.

What a cheap replica gives away

• Rounded, over-polished edges that make the case look like a pebble.
• Screw slots cut at random angles, or screws that are stamped rather than machined.
• A crooked bezel, uneven caseback seating, or a caseback that sits proud of the case.

Use case: spend your budget here first. Case finishing is the detail a knowledgeable eye reads before anything else.

Dial printing and hands

Cartier dials are printed, not stamped, and the letterforms carry small serifs that collapse in low-end copies. On the Santos, look at the spacing between the numerals, the weight of the minute track, and whether the Roman numerals sit level with each other. The seven o'clock numeral is the classic place to find a hidden signature on genuine Cartier dials; replicas often omit it or render it as a blur.

• Pros of a well-printed dial: the watch photographs correctly and the numerals hold up under a loupe.
• Cons of a cheap dial: thick paint, broken serifs, and hands that are too wide or too flat, all of which are permanent.

Use case: if you plan to photograph the watch or wear it in good light, the dial matters more than the movement.

Crown and cabochon

The Santos crown carries a blue synthetic spinel or sapphire cabochon set into a faceted crown. Genuine stones are cut with visible facets and a small table on top. Replica versions are frequently a flat blue dome, a painted dot, or a plastic insert that looks cloudy. Check the crown height too: a crown that sits too tall or too far from the case is a common replica error on this model.

• Pros: a correctly faceted cabochon is one of the cheapest upgrades a good replica factory can make, and it shows.
• Cons: glued cabochons fall out, and replacement stones rarely match the original cut.

Use case: this is the tell that survives bad lighting, so check it on any replica you intend to wear daily.

Bracelet and clasp

An integrated bracelet is only as good as its end links. On a replica Santos, open and close the clasp a few times, then check whether the links articulate without grinding and whether the bracelet drops straight from the case without a visible kink. Engraving inside the clasp should be crisp and centered. Screw heads on the bracelet should match the bezel screws in finish and slot depth.

• Pros of a solid bracelet: it holds the case flat on the wrist and hides gaps at the lugs.
• Cons: loose links, sharp edges on the underside, and a clasp that pops open are the most common complaints on mid-tier replicas.

Use case: the one thing to test in person if you can. Bracelet feel is hard to fake in photos.

Movement and the automatic claim

Several Santos references from the Galbée era left the factory with quartz movements, so an automatic is not automatically the correct specification. Before you accept an automatic as a sign of quality, confirm what the reference you are looking at actually used. On the replica side, a smooth sweeping seconds hand generally means a mechanical movement, while a ticking hand in one-second steps means quartz. A quartz movement inside a replica is not a defect by itself, provided the seller describes it honestly.

• Pros of quartz: less to service, more accurate day to day, thinner case.
• Cons of quartz: the ticking hand is visible, and the case may be built thicker to hide a spacer.

Use case: choose quartz if you want a low-maintenance wearer, mechanical if the sweep matters to you.

The three replica grades you will meet

Budget tier

• Pros: low cost, fine for a costume look at a distance.
• Cons: soft case edges, flat cabochon, printed dial that smears, hollow bracelet.

Use case: a novelty purchase only. Do not expect it to pass inspection.

Mid tier

• Pros: correct case proportions, decent bezel screws, acceptable dial printing, solid bracelet.
• Cons: finishing still slightly soft at the bevels, cabochon may be glued, clasp engraving inconsistent.

Use case: the sweet spot for most buyers who want the look without chasing every micro detail.

High grade

• Pros: sharp case lines, even screw slots, clean dial print, faceted cabochon, tight end links.
• Cons: highest cost, still a replica, and still worth verifying part by part before you pay.

Use case: buy this tier if the watch will be handled by other enthusiasts or photographed close up.

Quick inspection checklist

1. Measure the case and compare it to the reference you asked for.
2. Run a fingernail along the case bevels. Sharp is good, rounded is not.
3. Line up the bezel screws. Slots should read the same way around the dial.
4. Loupe the dial print and look for the hidden signature area at seven o'clock.
5. Inspect the cabochon for facets rather than a flat blue dome.
6. Flex the bracelet and listen for grinding, then test the clasp twice.
7. Ask what movement is inside, and match the answer to the ticking or sweeping hand.

Bottom line

Reference 162351 is a search term, not a guarantee. The replica market lives on that gap. Judge the watch you are actually being shown: case finishing first, dial print second, cabochon and bracelet third, movement last. A seller who answers specific questions about those four areas, and who does not hide behind a reference number, is the one worth buying from.