Strap for Oris Big Crown 01 645 7629 4064

The Oris Big Crown 01 645 7629 4064 features a 22-millimetre lug width. This measurement refers to the distance between the two lugs (horns) on the case where the strap is attached. To verify compatibility with aftermarket straps, measure the internal gap perpendicular to the lugs: the value must be exactly 22 millimetres for proper fitment.

For an aviator-derived watch of this calibre, vegetable-tanned leather—such as Tuscan leather—is the primary choice: it ages naturally and develops unique patina. Alligator represents the most refined option, with regular, geometrically-defined scales. For sports use or wet environments, ballistic NATO fabric or FKM rubber provide complete water resistance and minimal maintenance. Smooth calf leather offers the classical compromise between immediate suppleness and rapid patination.

Obtain a spring bar removal tool, a small two-pronged lever designed to lift the internal spring mechanism of the lug without damaging the case. Place the watch on a soft surface, insert the tool into one of the access holes on the lug, gently elevate the spring bar, and slide out the existing strap. Repeat on the opposite side, then align the new strap with the lugs and press the spring bar until you hear or feel a decisive click confirming proper seating.

Yes, any aftermarket strap with a precisely-engineered 22-millimetre lug width is compatible. Milanostraps curates an extensive selection of artisanal straps in leather, NATO, and rubber, all verified for this specific case dimension. Avoid straps with loose dimensional tolerances: an incorrectly-sized lug can cause accidental strap detachment during wear.

A quality leather strap, under ordinary wear conditions, typically lasts 3 to 5 years. Longevity depends on usage frequency, humidity exposure, and the tanning method employed. Vegetable-tanned leathers develop a protective patina naturally over time but benefit from occasional conditioning treatments. Rubber and NATO materials are more resistant to environmental degradation and may provide service for 7 to 10 years with minimal maintenance.