Strap for Divers Sixty-Five 40 Social Club Edition / Vienna

The lug width is 20 millimetres. This dimension refers to the distance between the lug pins on the case, defining the space available for strap insertion. Verifying this measurement before purchasing an aftermarket strap ensures both mechanical compatibility and aesthetic proportion with the case.

The choice depends on usage context and aesthetic intention. For instrumental use and diving, an FKM rubber or neoprene strap is recommended for salt-water resistance. For formal daily wear, an alligator or shell cordovan leather in satinized finish. For nautical versatility, a NATO strap in polyamide with neutral colourways (navy blue, black, grey). The strap must respect the 20mm lug width and maximum thickness of 4.5–5 millimetres.

The procedure is straightforward. Use a spring bar tool—a flat steel or brass instrument—to apply pressure on the ends of the horizontal pins securing the strap to the case. Once pressed, the pin retracts, allowing strap removal. Insert the new strap into the space between the lugs and press gently until the pin locks into place. Verify symmetry before wearing the watch.

Yes. The finest aftermarket straps are crafted in vegetable tannage or derived from integrated hide, available in alligator, calf, or cordovan. High-quality polyamide NATO straps and FKM rubber models are also compatible. The critical factor is selecting suppliers who maintain strict 20mm lug width tolerances and employ finishing techniques—stitching, rivets, passants—that prevent micro-friction on case edges.

A vegetable-tanned or shell cordovan strap, if kept dry and protected from excessive moisture, typically lasts 3–5 years of regular wear. Leather naturally ages, developing patina and tonal shifts. If frequently exposed to water, perspiration, and chemical agents (chlorine, salt), longevity reduces to 18–24 months. An FKM rubber or polyamide NATO strap resists degradation for 7–10 years, provided it is shielded from prolonged UV exposure and extreme temperatures. Deterioration is gradual; replacement is warranted when fibres fray or stitching loosens.