Strap for Seamaster 300 Master Co-Axial Titanium / Blue / Strap

The lug width of this model is 21mm. This measurement is specific to the 41mm Seamaster 300 and is essential to ensure strap compatibility: it must be measured precisely by positioning a calliper perpendicular to the inner side of the lug bar, from the left contact point to the right contact point on the case.

For the Seamaster 300 in titanium, alligator leather represents the most sophisticated formal solution: the natural scales dialogue with the modernity of the metal, and the patina that develops over time tells the story of the watch's use. Alternatively, textile NATO is the radical choice to underscore its underwater military heritage. The ideal strap thickness is 2–2.5mm to maintain the flexibility required by titanium lugs.

The strap is changed by extracting the spring bars from the lateral cavities of the case using a dedicated tool or a thin-bladed screwdriver. Position the tip on the spring bar until the internal spring compresses, then extract gently. Repeat on both sides, insert the new strap into the lug and verify that both spring bars click firmly into place.

Yes, any strap manufactured in compliance with DIN 3384 specification with a 21mm lug width is compatible with the Seamaster 300 titanium. However, it is advisable to choose thicknesses between 2 and 2.5mm: overly thick straps may not fit easily into the lugs, while undersized straps may not adhere securely. Atelier Casati Milano personalises every strap based on the exact specifications of your watch.

Durability depends on the material and usage. An alligator or vegetable-tanned calf leather, with regular maintenance (occasional cleaning, drying after water exposure), maintains structural functionality for 5–7 years of daily use. FKM rubber guarantees superior durability (8–10 years) as it is not subject to biological degradation. Atelier Casati Milano provides an 18-month warranty on every strap, with the option of regeneration or replacement if necessary.