Strap for Speedmaster Broad Arrow Platinum / Skeleton

The lug width is 20mm. This measurement corresponds to the inner lugs of the platinum case and represents the compatibility standard for all aftermarket straps. Measure the gap between the lugs with a digital caliper to verify accuracy before purchase.

For a platinum case, genuine alligator is the most noble choice: it offers structural durability, elegant aging, and a patina that evolves over time without deteriorating. Vegetable-tanned calf leather is an alternative if you desire more pronounced and rapid color evolution. For intense daily use, FKM rubber or a silk NATO strap ensure moisture resistance.

The 3658.50.31 uses fixed lugs with straight 20mm terminals. For replacement, remove the old strap using a spring bar tool: insert the flat tip under the spring of the first lug to compress it, then extract the pin. Repeat on the opposite lug. Install the new strap by reversing the procedure, ensuring that the terminals are well centered in the lug holes.

Yes, any strap with 20mm terminals is compatible with the 3658.50.31. Custom leather straps in alligator, calf, or vegetable-tanned leather from milanostraps.it have been tested and fit perfectly to the platinum case while maintaining the technical functionality and original aesthetics of the watch.

Durability depends on material and usage. Premium quality alligator resists 5-7 years with daily use before requiring aesthetic replacement (while maintaining functionality). Vegetable-tanned calf lasts 3-5 years with progressive visible wear of the patina. A NATO or rubber strap lasts over 10 years if kept dry. The Casati Milano atelier offers an 18-month warranty on every custom strap made.