Rolex
Day-Date 36 118139-0007— lug 20mm

The lug width is precisely 20mm, the factory standard for the Day-Date 36 collection. This measurement refers to the distance between the two fixed lugs (spring bar seats) integrated into the case where the strap is attached. It is essential to measure this distance accurately before purchasing any aftermarket strap, as even variations of 1-2mm render a strap incompatible or improperly fitted. A strap too narrow will not seat properly; one too wide will create gaps between case and strap, compromising the refined proportions Rolex has engineered.

Alligator remains the classical and most versatile choice: its natural grain contrasts elegantly with the luminosity of white gold, and a dark brown alligator (mahogany or deep chestnut) communicates formality without excess. Shell cordovan offers a refined alternative, distinguished by superior cellular density and a patina that evolves authentically over time. For contemporary versatility, vegetable-tanned calf allows eclectic colourways—navy blue, forest green—whilst maintaining artisanal integrity. Quality rubber on a deployant clasp represents an intellectual choice for those seeking to balance formality with sophisticated sportiness.

The procedure requires a proper spring bar tool with two opposing points. Position the tool so both points compress the spring bar ends simultaneously, creating a gap of 2-3mm to release the bar from its fixed lug seat. This must be executed with precision to avoid scratching the white gold case; it is strongly recommended to entrust this operation to an experienced jeweller or to Casati Milano's workshop if you prefer professional execution and peace of mind.

Yes, provided they respect the 20mm lug width specification and are manufactured by specialised artisans. Quality aftermarket straps from established makers (such as those from milanostraps.it or Casati Milano) offer construction quality equal to or exceeding the original factory strap, often with more discerning material selection. Warranty is a critical parameter: always purchase from makers guaranteeing a minimum 12-18 months against manufacturing defects. An artisanal strap in alligator or cordovan, if executed with craftsmanship, preserves both the value and aesthetic harmony of your Rolex.

Longevity depends on material, tanning method and wear frequency. A quality artisanal alligator or shell cordovan strap, worn daily and exposed to ordinary humidity, typically lasts 3-5 years before showing significant wear signs (thread failure, loss of lustre). Vegetable-tanned calf tends to age more rapidly, 2-3 years, developing patina alongside fragility. A superior-quality rubber strap on a deployant typically endures 5-7 years. Maintenance extends longevity: avoid prolonged soaking, exposure to salt water, and direct heat drying. A Casati Milano artisanal strap, constructed to Haute Couture standards, is engineered for conscious ageing and repair at the original workshop should any failure occur.