Strap for Fifty Fathoms Bathygraphe Jour Date 70’ Stainless Steel / Brown / Darkbrown Calf

The Blancpain Fifty Fathoms 5052-1110-063A features a 23mm lug width. This measurement represents the distance between the two lateral spring bars that secure the strap to the case. It is the standard specification for 43mm Fifty Fathoms models, ensuring balanced proportions and functional stability during wear.

We recommend alligator leather for daily elegance, vegetable-tanned calf for evolving patina over time, or structured rubber for professional diving and technical contexts. The choice depends on your intended use: casual-formal wear, collecting, or operational demands. All materials must be sized for 23mm lugs and mounted on proportionate passants.

Use a sprinksprocket tool or precision tweezers to gently extract the spring bars from the lateral lugs. Align the new strap's holes with the spring bars and gently reinsert the bars until you feel a secure click. Avoid hammers or excessive force to prevent damage to the case lugs.

Yes, provided the strap is properly manufactured for 23mm lugs. Verify that the passants are proportionate to the 43mm case diameter and that the chosen material (alligator, calf, rubber) suits professional use. Casati Milano specialises in bespoke made-to-measure straps with an 18-month warranty against manufacturing defects.

A quality leather strap (alligator, shell cordovan, vegetable-tanned calf) typically lasts 4–6 years with moderate daily wear. If exposed to frequent saltwater or constant tension in a professional diving environment, durability reduces to 2–3 years. Keeping the leather dry, avoiding thermal shock, and occasionally applying natural oil (not silicone-based products) significantly extends functional lifespan.