Rolex
Datejust 31 178383-0021— lug 16mm

The Datejust 31 reference 178383-0021 features a lug width of 16 millimetres. This is the distance between the case lugs where the leather strap passes are fitted. Any aftermarket strap must be precisely 16mm wide to ensure perfect compatibility and secure attachment without play or stress on the case.

For the Datejust 31 178383-0021 in the Rolesor configuration (steel and yellow gold), we recommend straps in genuine alligator or premium calf leather. Alligator represents the most prestigious choice due to its distinctive texture and the patina it develops over time. Calf leather offers a versatile and durable alternative, ideal for those seeking formal aesthetics without the more delicate care that alligator requires.

To change the strap, you must remove the spring bars using a specialised spring bar tool. Position the watch so the lug is accessible, insert the tool into the small slot beneath the lug, apply gentle pressure to compress the internal spring and withdraw the bar. Repeat on the other side. Once the old strap is removed, insert the new spring bars into the lugs and ensure they are fully seated until you feel the click. If unsure, contact an authorised Rolex dealer or a qualified watchmaker.

Yes, provided the strap is designed for the 16mm lug width. Milano Straps offers bespoke artisanal straps compatible with your Datejust 31 in various materials—alligator, calf, vegetable-tanned leather—available either made-to-order or from ready stock. What matters is verifying that the attachment points are precisely 16mm wide and that the material and style are coherent with your Rolex's aesthetic. A high-quality aftermarket strap can renew your wearing experience without compromising the value of the watch.

The lifespan of a leather strap depends on material quality, frequency of use and maintenance. A premium alligator or calf strap, worn daily, may last 3-5 years before showing significant signs of wear. If worn occasionally, longevity extends easily to 7-10 years. Vegetable-tanned leather tends to be more fragile but develops a fascinating patina with age. Milano Straps offers an 18-month warranty against manufacturing defects and can provide support for periodic maintenance and strap renewal.