Technical Archive

Rolex
Day-Date 40 228206-0012— lug 20mm

Rolex Day-Date 40 228206-0012: 20mm strap. Alligator, box calf, shell cordovan and rubber, cut and stitched in Milano. Choose your leather.

Day-Date 40 Platinum / Silver - Diamond

Artisanal Note

"This model requires a precise 20mm lug width to preserve the original sartorial balance."

Technical Specifications

Rolex 228206-0012
Lug Width
20 mm

The essential strap measurement.

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Reference

228206-0012

Movement

Rolex caliber 3255 Hours, Minutes, Seconds | Date, Day | Chronometer

The Heritage

The Rolex Day-Date 40 reference 228206-0012 is a 40mm platinum case watch introduced in 1956 as the first simultaneous day and date display timepiece. The 950 platinum case features a distinctive texture and finish, powered by the automatic calibre 3255 with Chronergy escapement, 70-hour power reserve, and COSC Chronometer certification (±2 seconds per day). The double window at 12 o'clock displays day and date in large readable characters. The strap lug width is 20mm, a standard Rolex dimension requiring correctly shaped strap ends for proper fit and visual continuity with the case.

FAQ

What is the lug width of the Rolex Day-Date 40 228206-0012?

The lug width of the Rolex Day-Date 40 reference 228206-0012 is 20mm. This measurement is taken between the two inner horns of the platinum 950 case and remains consistent across the entire Day-Date 40 family, regardless of case material or dial configuration.

What is the best strap for the Rolex Day-Date 40 in platinum?

For the platinum Day-Date 40, an alligator strap in vegetable-tanned leather represents the most coherent material pairing: the dorsal tile pattern develops a patina over time that complements the visual depth of platinum 950. Shell cordovan, with its compact, grain-free surface and dry lustre, is equally well-suited for a formally austere result. In both cases, a satin-finished steel or platinum deployant clasp completes the proportional balance.

How do you change the strap on a Rolex Day-Date 40?

Replacing the strap on a Rolex Day-Date 40 requires a fine-tipped spring bar tool. The spring bars are housed within the case lugs; compressing their ends releases the original bracelet or strap. It is advisable to work on a soft surface to protect the platinum case from scratches. For timepieces of this value, entrusting the operation to a qualified watchmaker or the Casati Milano atelier is strongly recommended.

Are there aftermarket straps compatible with the Rolex Day-Date 40 228206-0012?

Yes. Any strap with a 20mm lug width and end-pieces shaped to follow the curvature of the Day-Date 40 lugs is compatible. Bespoke straps crafted by Casati Milano for this specific model respect the original lug geometry, ensuring a flat fit and visual continuity with the platinum case. The total strap length should be verified against the wearer's wrist circumference.

How long does a leather strap last on a Rolex Day-Date 40?

The lifespan of a leather strap depends primarily on the hide, the tanning method, and daily maintenance. A vegetable-tanned alligator strap, kept away from prolonged moisture and periodically treated with neutral wax, retains its structural and aesthetic integrity for 3 to 5 years with regular wear. Shell cordovan, due to its dense fibre structure, typically lasts longer and develops an increasingly refined patina over time. Casati Milano straps carry an 18-month warranty against manufacturing defects.

The next step

The right strap isn’t chosen. It is built, together.

From the atelier appointment to delivery, every step is made for those who know that things done well take time. Rare leathers, one piece at a time, eighteen months of warranty.

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