What is Flange?

The flange is an angled ring positioned between the dial and the crystal of a watch, often serving both functional and aesthetic purposes. Sometimes referred to as a rehaut, though subtle distinctions exist depending on context and watchmaking tradition, the flange plays a significant role in framing the dial, supporting structural components and enhancing legibility through printed or engraved markings. Its seemingly modest presence masks its importance in the overall architecture of a wristwatch, where precision, visual balance and durability must coexist harmoniously.

As watch design has evolved from classical simplicity to include more elaborate multi level constructions, the flange has become an expressive design element. Whether engraved with minute tracks, branding or decorative textures, or simply polished to reflect light, it contributes to the visual depth and identity of a timepiece. Understanding the flange offers insight into how dial layouts are conceived and how watchmakers optimise internal space within the case.

Definition and Function of the Flange

At its core, the flange is a ring shaped component situated at the perimeter of the dial, rising at an angle toward the crystal. Its primary function is to bridge the gap between the flat plane of the dial and the vertical walls of the case, creating a smooth transition and protecting the dial from direct contact with the crystal. The angle of the flange provides additional space for markings that cannot easily be accommodated on the dial itself.

Its functions include:

Supporting minute or seconds scales for enhanced legibility.
Providing structural reinforcement between the dial and case.
Creating visual depth and framing the central dial.
Housing branding elements or serial numbers in certain designs.

While subtle, the flange influences reading accuracy, especially on watches with busy or multi layered dials.

Relationship Between Flange and Rehaut

The terms flange and rehaut are often used interchangeably, though some watchmakers distinguish between them. In a technical sense, the rehaut refers to the inner wall of the case that rises vertically, while the flange is the angled ring that connects the rehaut to the dial. In many modern watches, however, the two elements are integrated into a single continuous part, blurring the terminology.

What remains consistent is that this interior ring plays an important role in both structure and design. Enthusiasts, collectors and brands may use either term, but the functional concept remains similar.

Design Variations of the Flange

Flanges come in a wide variety of styles depending on the design language of the watch. Their angle, height, finish and functionality can differ significantly.

Common variations include:

Angled flanges with printed minute tracks.
Engraved or milled flanges for permanent markings.
Polished, brushed or bead blasted finishes for visual contrast.
Multi part flanges that incorporate luminous elements.
Vertical flanges used for branding or decorative inscriptions.

The choice of design affects how the watch is perceived, whether sporty, technical, elegant or minimalist.

The Role of the Flange in Legibility

One of the most valuable contributions of the flange is its ability to enhance legibility, particularly for minute or seconds readings. By moving the minute scale outward onto the angled ring, designers can free space on the main dial, reduce clutter and create better separation between indices.

The angled surface can also improve viewing angles. Because it slopes upward, printed or engraved markings remain visible even when the wrist is tilted, a useful feature in sport watches, pilot watches and chronographs where quick readings matter.

This design approach supports:

Cleaner dial layouts.
Wider spacing between minute markers.
Better accuracy when aligning hands with scale segments.

The result is an ergonomic improvement informed by real world use.

Integration with the Crystal and Case

Structurally, the flange sits between the crystal and the dial, contributing to case rigidity. In some watches, the flange forms part of the tension ring system that secures the crystal in place, particularly in models with acrylic domes or mineral crystals. It can help distribute pressure evenly, reducing stress points and enhancing water resistance.

The flange may also hide the edge of the dial, the dial feet or the gasket that seals the crystal. This contributes to a cleaner aesthetic by concealing functional elements without sacrificing performance.

In watches with sapphire crystals, the flange often interacts optically with the crystal’s inner bevels, creating interesting light effects that enhance perceived depth.

Materials Used for Flanges

The flange is typically made from metal, but the specific choice of material depends on the type of watch and the manufacturer’s design priorities.

Common materials include:

Stainless steel, valued for durability.
Brass, often used when the flange will be coated or printed.
Aluminium, offering lightness and ease of machining.
Titanium, found in tool watches for strength and low weight.
Precious metals, used in haute horlogerie pieces.
Composite materials or ceramic in modern high tech designs.

Coatings may include galvanic treatments, PVD or DLC finishes, lacquering or enamel printing depending on aesthetic requirements.

Flanges in Sport and Tool Watches

Sport watches often make prominent use of flanges to support technical scales. Dive watches may place minute hashes or depth conversion scales on the flange for quick reference underwater. Pilot watches may use the flange to position a wide, high contrast minute ring, echoing the design language of cockpit instruments.

In racing chronographs, the flange may serve as the site for tachymetric or telemetric markings. The stability and visibility of these scales ensure that they remain unaffected by dial interference when recording measurements.

Flange Engraving and Customisation

Engraved flanges have become a distinctive design trend in both luxury and independent watchmaking. Engraving provides permanence, depth and tactile appeal that printed markings cannot replicate. The engravings may include:

Minute or seconds scales.
Repeating patterns.
Model names or series identifiers.
Brand mottos or aesthetic motifs.

High end engraving may be performed by hand, requiring skill and precision, while industrial engraving techniques produce consistent, sharp markings suitable for sport watches.

Some brands use the flange to display serial numbers or limited edition information, subtly reminding the wearer of the watch’s exclusivity.

Interaction with Dial Architecture

The flange is a key component in multi level dial constructions. Its angle creates a natural separation between dial centre and minute track, allowing designers to introduce features such as applied indices, recessed subdials or layered materials without compromising clarity.

The flange can also function as a transitional zone between dial textures. For example, a watch may feature a guilloché centre with a brushed chapter ring and a polished flange, creating depth through contrasting finishes.

In skeletonised watches, the flange is often retained even when much of the dial is removed, helping preserve readability despite the open architecture.

The Flange as a Branding Element

Modern luxury watches increasingly use the flange for discreet branding. Text placed on the flange can remain subtle, visible only at certain angles. Some brands use repeated motifs, such as logos or names, engraved or embossed in a pattern around the ring.

This approach allows branding without overwhelming the dial, maintaining a balance between identity and elegance.

Flanges in Haute Horlogerie

In haute horlogerie, the flange becomes an artistic component. It may be:

Hand polished to achieve mirror like reflections.
Decorated with engine turning.
Crafted from gold or platinum to match case materials.
Skeletonised or pierced to create symbolic motifs.
Inlaid with enamel or other decorative materials.

These treatments elevate the flange from a functional part to a fine decorative element, demonstrating the craftsmanship that defines high end watchmaking.

Maintenance and Replacement Considerations

Although the flange is a durable component, it can require attention during servicing. Printed markings may fade over time, especially in watches exposed to moisture or sunlight. Scratches may appear on polished flanges if improper tools are used during disassembly.

Watchmakers must take care when removing or reinstalling the crystal to avoid damaging the flange. In some designs, the flange is integrated into the case and cannot be replaced separately, while in others it is a removable ring.

Proper maintenance ensures the flange retains its clarity and contributes to the watch’s legibility and aesthetic integrity.

The Flange in Contemporary Design Trends

In modern watchmaking, the flange has become more prominent as brands explore multi dimensional dial construction. Trends include:

Wider flanges to create depth and framing.
Use of lume filled flanges for night time visibility.
Colour contrast flanges to highlight minute tracks.
Engraved patterns extending beyond purely functional markings.

These trends reflect a growing appreciation for how the interior geometry of a watch can shape its overall presence.

Conclusion

The flange is far more than a transition between dial and crystal. It is a functional, structural and aesthetic component that contributes significantly to legibility, design harmony and case engineering in a wide range of watches. Whether engraved with precision markings, polished to catch the light, or subtly integrated into the case architecture, the flange plays a meaningful role in both everyday and high end horology.

As watch design continues to evolve, the flange remains an essential element that bridges tradition and modernity, offering watchmakers a versatile canvas for technical utility and creative expression.