Strap for Fifty Fathoms Automatique Stainless Steel / Black / Bracelet

The lug width (spring bar distance) of the Blancpain Fifty Fathoms 5015-1130-71S is 23mm (23.00mm with tolerance ±0.5mm). This specific measurement is characteristic of the larger Fifty Fathoms models and was engineered to accommodate thicker straps, essential for distributing the watch's weight correctly during extended dives and intensive daily use.

The choice depends on your intended usage. For formal-elegant wear, alligator leather in dark tones (mahogany or black) represents aesthetic excellence. For frequent water use, a natural or synthetic rubber strap offers superior grip and durability. A military NATO remains the most versatile and practical solution, particularly if you alternate between urban settings and offshore activities. For those who appreciate visible patina development, shell cordovan is the most refined choice, though it requires careful maintenance.

Strap replacement is performed using a spring bar tool to extract the two spring bars from the watch lugs. Position the tool in the side slot of the spring bar, press gently downward, and extract the bar completely. Repeat on both sides, then insert the new strap by aligning the holes with the lugs and pressing the spring bars until fully seated. Verify that each bar is perfectly positioned to prevent accidental dislodgement during diving.

All straps with a 23mm lug width are compatible with the 5015-1130-71S. The range includes alligator, calf, crocodile, shell cordovan, NATO, natural and synthetic rubber. It is essential to verify that the strap has been specifically designed for this width, as an incorrect measurement would result in bezel instability and detachment risks during diving. Milano Straps provides a comprehensive selection of 23mm custom straps.

Durability depends on material quality, maintenance regimen, and usage intensity. High-quality alligator or calf leather, used occasionally, can last 3-5 years before requiring replacement. If the watch is frequently immersed in water, lifespan reduces to 1-2 years. A rubber strap has virtually indefinite durability if rinsed periodically in fresh water. Vegetable-tanned leather develops superior patina with regular maintenance and can remain intact for over 10 years. Casati Milano offers an 18-month warranty on all manufacturing defects.