Strap for Speedmaster 57 Co-Axial Stainless Steel / Silver / Bracelet

The lug width is exactly 20 mm. This dimension is specific to the Speedmaster '57 and is calibrated to maintain balanced proportions with the 41.50 mm case. To verify the lug width of your watch, place a ruler between the two inner lugs: the distance should be 20 mm. This specification is essential for selecting a compatible strap.

The best strap depends on your intended use and aesthetic preferences. Vegetable-tanned alligator is the most historically coherent choice, echoing the original strap designs from the 1950s. Shell cordovan offers a striking aesthetic alternative, with its color shifting from burgundy to mahogany over time. Hand-stitched barrel-dyed calf represents a balance between tradition and everyday practicality. For intensive sporting contexts, a ballistic nylon NATO strap offers maximum resistance.

The strap is changed using specific tools: a spring bar tool and careful handling. First remove the detachable lugs: insert the tip of the spring bar tool into the thin groove between the lug and the strap pin, press gently downward to release the spring, then slide the lug outward. Once the spring is extracted, lift it from its seat. To install the new strap, reverse the process: insert the spring into the seat, reposition the lug, then use the spring bar tool to lock the end into the lug hole. Always verify that the lug is securely fastened before wearing the watch. If you are unsure, Casati Milano offers a strap change service by appointment.

Any strap with a 20 mm lug width is compatible with the Speedmaster '57. Online you will find a wide selection of 20 mm straps ready for shipping, customizable in size, initials, and stitching thread. The Casati Milano atelier also creates custom leather straps with personal leather selection, allowing you to choose the material (alligator, shell cordovan, calf) and finish that best reflects your style.

The lifespan of a leather strap depends on the material, frequency of use, and environmental conditions. An alligator or shell cordovan in vegetable tanning, with proper care (avoiding prolonged exposure to sun and humidity), can last from 3 to 5 years before showing significant signs of wear. A barrel-dyed calf offers comparable durability, with the patina improving over time. Casati Milano straps include an 18-month warranty. Longevity increases if the strap is rotated regularly: having multiple straps for your Speedmaster '57 extends the life of each one by distributing the wear load.