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

The Omega Speedmaster '57 (reference 331.10.42.51.03.001) features a 20 mm lug width, conforming to the NATO STANAG 4204 standard. This size is proportionate to the 41.5 mm case and allows pairing with quality artisanal straps without compromise.

For this chronograph we recommend alligator with fine grain (formal-sporty contrast) or shell cordovan that develops natural patina over time. Alternatively, vegetable-tanned calf balances flexibility and longevity. The choice depends on usage environment: formal suggests alligator, daily wear prefers calf, sporty favors fabric NATO.

Obtain a spring bar removal tool. Place the watch with the dial facing down. Locate the two metal pins at the case ends. Insert the tool into the hole above the pin and apply light downward pressure: the pin will slide out. Repeat on the other side. Remove the old strap, align the new strap's pins with the case holes, and push until the safety click engages.

Yes, any strap marked 20 mm NATO (STANAG 4204) is compatible. Always verify the lug depth (distance from case back to strap end) to ensure the strap does not pinch against the case. Artisanal straps can be customized in width and thickness to accommodate your case's individual tolerances.

A quality leather strap (alligator, shell cordovan, vegetable-tanned calf) typically lasts 3–5 years with daily wear, depending on exposure to moisture, perspiration, and sunlight. Vegetable tanning is more resilient to moisture, while alligator requires protection from water stains. Periodic maintenance—cleaning with a damp cloth and annual conditioning—extends useful life to 7 years.