Strap Guide — A Guide to Cartier Folding Clasps and Their Strap Constructions

For many Cartier collectors, the original folding clasp is an important part of the watch.

Preserving it maintains not only the appearance of the watch, but also the way it feels and closes on the wrist. However, a replacement leather strap must be constructed specifically for the clasp to which it will be fitted.

There is no single universal “Cartier clasp strap.” Cartier has used different folding-buckle constructions across individual references, and the way the leather connects to the hardware can vary considerably.

Below are four configurations for which Atelier Tamago has previously created bespoke straps.

The names used in this guide primarily describe the strap-to-clasp construction. With the exception of Cartier’s official term Interchangeable Folding Buckle, they are not intended to represent an official or exhaustive Cartier classification.

1. Cartier Folding Clasp with Two Folding Strap Ends

This configuration is commonly described by strap makers as a double-fold clasp arrangement.

Both leather strap ends pass through the clasp and fold back into the hardware. Unlike a conventional tang-buckle strap, the two sides do not use a standard row of adjustment holes.

This creates a clean appearance on the outside of the strap. Because the two folding ends can be positioned separately within the clasp, the effective length can also be balanced from both sides, helping the clasp sit more naturally beneath the wrist.

A strap made for this configuration requires:

• Two extended folding ends
• Carefully reduced thickness at both clasp ends
• Sufficient flexibility to fold neatly within the hardware
• No conventional tang-buckle hole pattern
• No standard buckle attachment or keeper arrangement

The thickness of the folding sections is particularly important. If the leather is too thick, it may not pass through the clasp cleanly or may create unnecessary bulk once folded.

A standard tang-buckle strap cannot normally be fitted to this clasp simply by removing its buckle. The lengths and both clasp ends must be prepared specifically for the folding configuration.

2. Cartier Folding Clasp with One Adjustable Folding End

With this configuration, the two strap sides are constructed differently.

One side attaches directly to the clasp, while the other passes through the retaining section and folds back into the hardware. The wearing length is adjusted by changing the position of this folding end.

A compatible strap therefore requires:

• One flat clasp attachment
• One extended folding end
• Reduced thickness at the folding section
• A specific long-side and short-side orientation

The two strap pieces are not interchangeable because their clasp ends serve different functions.

The orientation must be reproduced correctly so that the clasp opens in the intended direction and sits comfortably beneath the wrist. The existing strap is often the most useful reference, particularly when working with an older or less commonly encountered clasp.

Although this configuration may appear similar to the two-folding-end version when closed, the required strap preparation becomes clearly different once the clasp is fully opened.

3. Cartier Interchangeable Folding Buckle

Interchangeable Folding Buckle is an official term used by Cartier for its patented system.

Cartier states that the design was inspired by its original folding buckle and developed with particular attention to security, comfort and personalisation.

In this configuration, one strap side connects to the buckle head with a sprung bar. The opposite side contains a row of holes and is fed into an opening in the buckle. An internal picot engages with the selected hole to establish the wearing length.

A compatible strap must therefore include:

• One accurately prepared attachment end
• One perforated adjustment section
• Correct hole diameter and spacing
• Correct positioning of the holes in relation to the buckle
• Suitable thickness at both buckle connections

4. Vintage Cartier Fixed-Length Folding Clasp

Among the vintage Cartier folding clasps we have worked with, some use a fixed-length strap arrangement.

Rather than passing through the clasp and folding back, both leather strap ends remain flat and attach directly to the hardware. Once fitted, the clasp itself provides little or no routine adjustment.

The strap must therefore be made to the wearer’s measurements from the beginning.

A compatible strap requires:

• Two flat clasp ends
• Direct attachment to the original hardware
• No folding leather sections
• No conventional adjustment holes
• Precisely calculated long-side and short-side lengths

With this configuration, the total length is only part of the calculation.

The proportion between the two strap pieces determines where the clasp sits beneath the wrist. A strap can have the correct overall circumference but still position the clasp too far toward one side.

When the original strap fits well, reproducing its two individual lengths is usually the most reliable starting point. When it does not, the wrist circumference, watch-case length, clasp dimensions and present clasp position must all be considered together.

Vintage Cartier hardware can vary, so the attachment method should always be confirmed from the actual clasp rather than inferred from the watch collection alone.

Why We Confirm the Clasp After Your Order

The Cartier collection name alone does not always provide enough information to determine the required strap construction.

For this reason, we do not ask customers to identify the precise folding-clasp configuration themselves.

After receiving the bespoke strap order for Cartier Watch, we will contact the customer and request:

• The full watch reference, when available
• Clear photographs of the clasp fully opened
• Photographs showing how both strap sides connect
• Lug-width and clasp-end measurements
• Wrist circumference
• Existing strap lengths, when relevant

For a vintage fixed-length clasp, we may request additional measurements or a photograph showing the current position of the clasp beneath the wrist.

We review this information individually and confirm the required strap construction before production begins.

This allows us to prepare the new strap around the actual hardware, preserving the function, comfort and visual integrity of the original Cartier folding clasp.

Atelier Tamago is an independent strap maker and is not affiliated with or endorsed by Cartier. This guide presents strap constructions we have encountered through our bespoke work and is not intended as an official or exhaustive Cartier clasp classification.