Rolex
Day-Date 36 118348-0155— lug 20mm

The lug width of the Rolex Day-Date 36 118348-0155 is precisely 20 millimetres. This dimension is measured between the two suspension pins of the yellow gold case and is standard for all Day-Date 36 models. Any strap intended for this watch must be exactly 20 mm wide to fit correctly within the case lugs and maintain aesthetic balance.

For the Day-Date 36 in yellow gold, alligator leather remains the traditional and aristocratic choice, particularly in dark brown or cognac tones that harmonise with the natural patina of the gold case. Shell cordovan is ideal for those seeking a strap with intrinsic lustre and rapid patina development. Vegetable-tanned calf leather offers a sophisticated and more accessible alternative. For informal contexts, a 20 mm NATO or rubber strap provides functional versatility whilst maintaining the watch's prestige.

Strap replacement requires two tools: a spring bar removal tool and a stable work surface. Position the watch with the lugs facing upwards, locate the small elastic pin beneath the case, press gently with the tool to release the spring bar, and remove the old strap. Repeat on the other lug. Insert the new spring bars into the new strap and secure them by snapping the bars into the case lugs. If you lack experience, it is advisable to consult a professional watchmaker.

Rolex recommends using original straps to maintain the international warranty. However, the use of a quality aftermarket strap (such as those crafted by Casati Milano with premium leather and sartorial finishing) does not automatically invalidate the warranty, provided the watch has not undergone structural modifications to the case. It is important to retain the original strap and verify the specific warranty conditions with an authorised Rolex retailer.

The lifespan of a natural leather strap depends on the quality of craftsmanship and frequency of use. With vegetable tanning, a well-maintained strap typically lasts between 4 and 7 years of regular wear. Alligator and shell cordovan, owing to their superior fibre density, achieve 7-10 years of service. Natural patina is not deterioration but aesthetic enrichment: a worn strap, if maintained with simple precautions (brushing, protection from moisture), acquires character and ennobles the watch.