Strap for Big Crown Small Second Pointer Day Stainless Steel / Black / Bracelet

The lug width is 22 mm. This measurement represents the distance between the two attachment pins (spring bars). To verify compatibility, measure with a digital calliper between the inner shoulders of the pins: if the reading is 22 mm, any watch strap with this lug width will fit your Big Crown perfectly.

The choice depends on intended use and aesthetic preference. A vegetable-tanned leather strap imparts historical authenticity and develops a rich patina over time; alligator in cognac brown offers elegance and durability; a cotton NATO strap reflects the tool watch vocation and guarantees practicality. For an aviation timepiece with this heritage, we recommend robust leather or NATO – avoiding synthetic materials that would contradict the mechanical character of the Oris 645 calibre.

The Big Crown uses standard spring bar pin attachments. You will need a spring bar tool: insert the flat tip into the lower slot of the pin, lift slightly to release spring tension, then pull the pin outward. Repeat at the opposite lug end and remove the old strap. To install a new strap, align the holes at both case ends, insert the pins whilst maintaining gentle pressure until they engage naturally. Never force: the motion should be smooth and effortless.

Absolutely. The 22 mm lug width is a standard measurement: any artisanal strap produced for this width integrates without compromise. Quality aftermarket straps – in vegetable-tanned leather, alligator, shell cordovan or rubber – often offer superior aesthetic and tactile choice compared to factory options, allowing you to personalise the timepiece according to your wearing context.

Durability depends on material composition and usage patterns. A vegetable-tanned leather strap with medium-heavy gauge resists 3–5 years under daily wear, developing a compelling patina. Alligator can endure 5–7 years whilst maintaining impeccable appearance. Vulcanised rubber, more resistant to atmospheric agents, easily exceeds 5 years. Maintenance is straightforward: clean regularly with a soft cloth, apply conditioner every 6–12 months to natural leathers. When strap fatigue appears, replacement is quick and affordable.