Rolex
Datejust 31 278240-0013— lug 16mm

The Rolex Datejust 31 ref. 278240-0013 has a lug width of 16mm. This measurement should be taken internally between the two lugs using a digital calliper, pressed against the case, to ensure accurate compatibility with aftermarket straps.

For the Datejust 31 in Oystersteel, a vegetable-tanned alligator strap is the most refined choice for formal and semi-formal wear, as the grain develops a distinctive patina over time. Box calf leather is preferable for daily use, whilst a nylon NATO or FKM rubber strap suits sporting and aquatic environments.

To replace the strap, the spring bars must be removed from the lugs using a double-ended springbar tool. Insert the forked tip between the lug and the strap end piece, then compress the spring bar until it releases. The process takes approximately two minutes per side and does not require specialist watchmaking tools. It is advisable to work on a soft mat to protect the case finish.

Yes. Any strap with a 16mm attachment and standard spring bars is compatible with the Datejust 31 278240-0013. Milano Straps offers a curated range of handcrafted straps in 16mm width, including options in alligator, calf leather, NATO, and rubber. A fully bespoke service is also available through Casati Milano.

The lifespan of a leather strap depends on the material, frequency of wear, and exposure conditions. A quality vegetable-tanned alligator strap, used with care and rotated with other straps, can last between three and seven years. Contact with water, perspiration, and cosmetics accelerates deterioration; it is recommended to remove leather straps before aquatic or sporting activities.