Strap for Williams Day Date 42 Stainless Steel / Blue / Bracelet

The Oris Williams 01 735 7740 4155-07 8 24 50S features a 24mm lug width. This dimension is specific to 42mm case models and is essential for selecting compatible aftermarket straps. Correct measurement is taken from the base of one lug shoulder to the other, parallel to the case surface, ensuring the strap is fully inserted into the mounting slot.

Selection depends on intended use. For formal settings and seasonal rotation, genuine alligator in dark brown or black develops an evolving patina over time. For a versatile approach, Italian vegetable-tanned calf offers balance between tradition and daily practicality. For sports or humid environments, FKM rubber with fine-grain texture ensures tactile grip and minimal maintenance.

The Williams uses a reversible spring bar system. Position the strap face-down, locate the two small side holes on the lug, insert a dedicated flat tool (lug opener) to compress the spring bar toward the case centre, and gently extract the old strap. Repeat on the opposite side. Insert the new strap ensuring the spring bar clicks correctly and the strap sits fully in the mounting slot.

Any strap with a 24mm lug width is compatible. Milano Straps offers a dedicated 24mm strap collection in alligator, vegetable-tanned calf, NATO and FKM rubber. Always verify that manufacturing tolerance permits smooth insertion into the spring bar system, as some manufacturers maintain minimal tolerances on width.

Natural leather strap lifespan (alligator, calf, vegetable-tanned calf) ranges from 3 to 7 years depending on frequency of wear, climatic conditions and maintenance. Genuine alligator tends to last longer due to dermal fibre structure. Regular water exposure shortens lifespan; we recommend immediate air-drying after water exposure. Minimal maintenance with neutral conditioner every six months significantly extends service life.