Blancpain · Fifty Fathoms

Strap for Fifty Fathoms Automatique Titanium / Black / Sailcloth

Takes 23 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.

Lug width23 mm
Case diameter45 mm
Reference5015-12B30-B52B
FamilyFifty Fathoms
MovementBlancpain caliber 1315 hours, minutes, seconds | date
Year2007
CaseTitanium

Spring bar

Swiss Standard universal spring bars

The right category for this model · 316L steel, all lug widths 13–26 mm

The Fifty Fathoms 5015-12B30-B52B, seen from the bench

The Fifty Fathoms represents Blancpain's dive watch, originally introduced in 1953. It features the Blancpain 1315 automatic caliber with hour, minute, second, and date indications. The reference 5015-12B30-B52B has 23mm lugs.

Frequently asked questions

What is the lug width of the Blancpain Fifty Fathoms 5015-12B30-B52B?

The lug width is 23mm, measured from the centre of the holes on the case lug. This dimension is precise and admits no variation; it is essential to verify the compatibility of any aftermarket strap before purchase to ensure a perfect fit without lateral tensions.

What is the best strap for the Blancpain Fifty Fathoms 5015-12B30-B52B?

The choice depends on usage: alligator with vegetable tanning offers elegance and natural patina development; vegetable-tanned calf provides resistance and flexibility for daily wear; shell cordovan represents the premium option for those seeking natural water resistance and development of a mahogany-coloured patina. For frequent diving, natural rubber or technical nylon with titanium deployante offer uncompromised performance.

How do you change the strap on the Fifty Fathoms?

The procedure requires a dedicated lug remover tool to extract the spring bars that connect the strap to the case. Given the case circumference and precision required, we recommend contacting an authorised service centre or experienced professional to avoid damage to the titanium or screw-down crown. The process is not complex but demands care.

Which aftermarket straps are compatible with this reference?

All straps with 23mm lug width are theoretically compatible, but the geometry of the Fifty Fathoms case requires straps with pronounced downward curve for ergonomic fit. We recommend bespoke leather straps made specifically for this case, such as those available on milanostraps.it, which guarantee visual proportion and wrist comfort.

How long does a natural leather strap last?

A vegetable-tanned leather strap has a longevity of 5–8 years with daily use and regular maintenance (moderate cleaning, avoiding prolonged contact with unrinsed seawater). High-quality shell cordovan and alligator can exceed 10 years. Natural rubber maintains elasticity for 4–6 years before requiring replacement.

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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Casati Milano · Via XX Settembre 15, Milan · by appointment only