The JCB seal, testimony to our tireless quest for perfection

At the heart of our watchmaking philosophy is an unwavering commitment to achieving the pinnacle of craftsmanship and quality. We are driven by a relentless pursuit of excellence, aiming to elevate the art of watchmaking to unprecedented heights. Our dedication to innovation fuels our ambition to explore uncharted territories, break barriers and venture where others dare not. As this level of excellence is unrivalled today, we have developed our own seal, a testament to the Maison’s exacting standards. It’s the result of decades of experience, doubt, love and passion for watchmaking. Through this seal, we strive not only to set new standards, but also to inspire a new era of watchmaking wonders.

The JCB seal stands for the highest standards, such as water-resistance to 50 meters - a true technical feat for chiming watches - and decoration at the pinnacle of the watchmaking art.

Steel parts

• Wire springs are not permitted, neither are pressed or folded steels.
• Springs are to be machined from spring steel (LIGA process not permitted).
• The flanks of steel components are to be satin-brushed.
• All steel parts are to have polished chamfers.
• The top face of steel parts are to be either straight-grained or mirror-polished.
• The functional surfaces of the steel parts are to be polished.
• Screw and pin countersinks are to be polished.

Arbors

• All pivot surfaces are to be burnished.
• Pivot tips are to be dome-polished.
• The tip of the cannon pinion is to be dome-polished.
• Pinions and pivot shanks are preferably hand-polished.

Optional: The pinion toothing is preferably polished with a grinding wheel.

Wheels

• Wheels are to be pressed-riveted.
• Wheels are to be cut after the decoration has been applied (no galvanic treatment of the toothing).
• Wheels are to be circular-brushed on both sides.
• Wheel arms are to be chamfered on both sides.

Optional (depending on the design): Wheels should feature a diamond hub flange.

Bridges

• Bridge flanks are to be satin-brushed.
• All bridge chamfers are to be polished.
• The top face of the bridges is to be meticulously decorated (Côtes de Genève, sunray brushing, circular-brushed, snailing, satin-finishing etc.)
• All screw and pin countersinks are to be polished.
• To the extent possible, all bearings are to be jewelled.
• In case of chatons surrounding the jewels, these are to be in solid gold.

Escapement

• The escape wheel and pallet are to be mirror-polished.
• The pallet is to have polished chamfers.
• The index assembly is to have a fine high-end adjustment (e.g., Geneva balance spring stud, triangular balance spring stud).
• The index assembly is to be mirror-polished.
• The balance wheel is to be of the variable inertia type.
• The balance felly is to be diamond ground on the inner, outer and top faces. • The balance wheel is to be fitted with a shock absorption system.
• In a movement without a tourbillon, the escape wheel is to have end stones.

Optional: A Breguet overcoil balance spring is preferred.

Pins

• Pins must be dome-polished at both ends.
• Pins are preferable to shoulder screws.
• Pins are to be imperatively tapered to prevent burrs when driven in.

Screws

• Screw heads are to be chamfered and mirror-polished.
• Screw foot ends must be dome-polished.
• Case screws are preferably in stainless steel.

Tourbillon

• In a watch with a tourbillon, the upper tourbillon bridge and cage plate are to be meticulously finished (mirror-polished, chamfered, circular-brushed, satin-brushed etc.)
• Components are preferably made of titanium to minimize the tourbillon’s weight and improve chronometric performance.

Referencing

• The movement is to be identifiable with a calibre number and a movement number.

Automatic movement

• Oscillating masses are to be either in gold or platinum.
• The self-winding mechanism is to be bi-directional to exploit both directions of rotation.

Chronometric performance

• Movements must meet or exceed COSC rating requirements.

Build quality

• The stops of the winding shaft are to be firm and precisely locked in. There is to be no unnecessary movement and any play in the hands is to be minimal.
• Winding the crown is to be pleasurable (no grating, with a pleasant clicking sensation).
• A hacking seconds function is preferable.
• The movement is to meet the Chronofiable standard.
• Jumping indications for functions and complications are preferable (e.g., calendar).

Case

• The caseback is to be sealed with screws (no clip-on or screw-in backs).
• The bezel is to be secured with screws (not by pressure).
• Crystals (front and back) are to be made from sapphire with an anti-reflective treatment on the inner surface.
• There is to be no surface treatment on the case.
• The movement is to be cased-up gaplessly (without a casing ring).
• The movement is to be held place imperatively with stepped movement clamps. An exception may be made for minute repeaters, which are to be screwed directly onto the case.
• The movement clamps are to be made of stainless steel.
• The construction of the case must ensure it is water-resistant, even if the crown should be pulled out.

Hands

• Hands are to be made of 18K gold, except when subjected to significant mechanical stresses, e.g. chronograph hands.
• Where hands are blued, steel is permitted, provided the traditional flame-bluing process is employed. Galvanic, PVD or DLC treatments are not permitted.

Dial

• Indexes, applied markers and windows must be made of 18K gold.
• The back of the dial must be decorated (e.g., circular graining).

Gem-setting

• The quality of the gem-setting must be flawless.
• The diamonds used must have a minimum clarity of VVS1, and a colour rating of D to F.

Water resistance

• All watches are to be water-resistant to 5 ATM at least (equivalent to a depth of 50 metres.)

Test

All cased-up watches are subject to a final validation protocol. The protocol covers the following points:

• Water resistance
• Accuracy
• Power reserve
• Functions and/or other calendar indications
• Aesthetics and fit (case, dial, hands, movement, casing-up, bracelet, clasp etc.)

Warranty

Watches certified with the JCB Seal come with a 3-year warranty and are to be repairable throughout their lifetime.