Rolex
Datejust 31 278273-0027— lug 16mm

The lug width (also called ansa width) of the Rolex Datejust 31 278273-0027 is 16 millimetres. This measurement is essential when selecting a replacement strap: the strap must not exceed 16 mm in width to fit properly without gaps or overhang. You can verify the lug width using a digital calliper positioned between the two lugs.

For the Datejust 31 278273-0027 with mother-of-pearl dial and yellow Rolesor case, alligator leather in black or dark brown is the most refined choice: it creates elegant contrast with the pearlescent white and yellow gold, enhancing sophistication. Cognac calf is an excellent alternative if you prefer greater versatility. Vegetable-tanned leather works well if you appreciate the natural patina that develops over time.

Changing the strap requires a spring bar tool (a small dedicated lever) and careful technique. Position your watch securely, access the spring bars from the sides (tiny springs holding the strap to the lugs), press gently with the tool to compress them, and simultaneously slide the strap outward. To fit the new strap, align the holes, insert the compressed spring bar, and release. If unsure, consult an authorised Rolex service centre or a specialist watchmaker.

Yes, absolutely. A quality aftermarket strap with 16 mm lug width is fully compatible. Strap quality depends on material, craftsmanship and finishing: a strap in alligator or calf leather crafted by a specialised artisan such as Casati Milano provides durability and aesthetics equal to or surpassing Rolex originals, with greater colour versatility.

Lifespan varies according to material, usage and maintenance. A quality alligator strap typically lasts 5–7 years with moderate daily use; calf leather 3–5 years; vegetable-tanned leather 4–6 years with regular care (cleaning, light conditioning). Exposure to humidity, perspiration and UV rays accelerates ageing. Periodic maintenance (gentle conditioning) extends strap life considerably.