Strap for WilliamsF1 Team Day Date 40.5 Stainless Steel / Black - Blue / Bracelet

The lug width of the Oris Williams 01 635 7560 4145-07 8 25 01 is 35mm. This specific measurement ensures harmonious proportions on the 40.50mm case and requires straps constructed expressly for this dimension, excluding generic or universal models. The measurement is obtained by calculating the vertical distance between the centres of the two attachment pins.

For this motorsport model, an alligator strap with vegetable tanning in brown or black is recommended, as it emphasises the formal aesthetic without clashing with the dial. Alternatively, a long-grain calf leather in anthracite grey or a Racing NATO strap in navy blue with grey stripes (replicating the historic Williams livery) offers daily versatility. For aquatic environments, a black FKM rubber maintains the sports aesthetic with maximum functionality.

Obtain a spring bar tool (a small specialised instrument). Position the watch on a stable surface, take the curved end of the tool and insert the hook into the lower hole of the lug, lifting the pin gently. Repeat from the other side. Remove the old strap, align the new pins with the case attachments and snap the strap into place. Verify that both pins are securely locked.

Yes, provided the lug width is exactly 35mm. Artisanal straps from specialised suppliers (such as Milano Straps) often offer construction quality superior to OEM straps, with a selection of noble materials such as certified alligator, shell cordovan or long-grain calf. Always verify that the new strap is made for 35mm attachments and that the width at the base matches the case geometry.

A high-quality leather strap (alligator, shell cordovan, calf) subjected to moderate daily use typically lasts 3–5 years before replacement is necessary. Longevity depends on exposure to moisture, perspiration and the number of weekly wear changes. An FKM rubber or NATO strap resists 5–7 years with greater chemical resistance. Vegetable tanning develops a noble patina, whilst modern cells may present accelerated cracks if subjected to extreme thermal variations.