Strap for Speedmaster 57 Co-Axial Stainless Steel / Blue

The Ref. 331.12.42.51.03.001 has a lug width of 20 mm, which is the distance between the spring bars that attach the strap to the case lugs. This design specification is determined by the proportions of the 41.50 mm case and ensures perfect aesthetic alignment of the strap passant on the lateral flanges.

The Speedmaster '57 truly shines with a black alligator strap in vegetable tanning, which amplifies its historical formality and case symmetry. However, American shell cordovan offers a patina that evolves over time, while a grey-blue cotton NATO maintains vintage authenticity without sacrificing sports functionality.

The procedure requires a spring bar tool (two-pronged instrument). Position the tips into the lateral notches of the spring bars, one on each side, and compress to release the spring. The bar slides freely from the lug. For the new strap, align the holes at the ends and snap the bar into the opposite notches. Avoid forcing: Omega spring bars are constructed with precise tolerances.

Yes, provided it strictly adheres to the 20 mm lug width specification. Omega's manufacturing tolerance is ±0.5 mm, but a certified 20 mm strap will always fit without issues. Verify that the passant width is proportioned to your wrist (typically 20–22 mm visible width) to maintain aesthetic balance.

A high-quality alligator or shell cordovan strap lasts 3–4 years of daily wear with regular maintenance (weekly cleaning with a damp cloth, protective cream every 3 months). Durability depends on local humidity, sun exposure, and frequency of use. A cotton NATO strap resists wear for 2–3 years before showing visible edge deterioration.