Rolex
Day-Date 36 118238-0181— lug 20mm

The lug width (measure between lugs) of the Rolex Day-Date 36 ref. 118238-0181 is exactly 20mm. This specification is unique to the Day-Date 36 model and differs from the 19mm of other Datejust models or the 22mm found on modern Submariner references. To verify the measurement, use a digital calliper perpendicular to the lugs: the internal distance must read precisely 20.00mm.

For the Day-Date 36 in 18k yellow gold, an American alligator strap with natural patina creates the most harmonious aesthetic dialogue with the warm tone of the case. Vegetable-tanned calf leather is an elegant alternative for those preferring faster patina development. The ideal colour is cognac or dark brown, creating a refined visual contrast. FKM rubber is recommended for more sporty use and superior water resistance.

The Day-Date 36 strap is changed using an appropriately sized spring bar removal tool. Insert the flat tip of the tool into the small lateral hole of the lug, applying gentle pressure to compress the internal spring and release the pin. Remove the old strap and align the new pin with the opposite lug's hole, then press until you hear a click. Repeat this procedure on both sides of the case.

Yes, you can use quality aftermarket straps in the 20mm measurement on your watch. Ensure the strap is specifically constructed for 20mm lug width, as even minor discrepancies will cause installation difficulties or unwanted lateral play. Custom-made straps from specialised ateliers, such as Casati Milano, guarantee perfect fit and superior materials.

The lifespan of a leather strap depends on material type, usage intensity, and maintenance. Quality American alligator typically lasts 3–5 years with daily wear, whilst vegetable-tanned calf tends to last 2–3 years. FKM rubber offers extended longevity, up to 5–7 years. Factors such as sun exposure, humidity, and perspiration accelerate ageing. Regular maintenance with specialised products significantly extends strap life.