Rolex
Datejust 31 178313-0041— lug 16mm

The lug width of the Rolex Datejust 31 reference 178313-0041 is 16 mm. This measurement is taken between the lugs at the point where the strap attaches to the case. Respecting this dimension is essential to ensure the strap fits correctly and sits proportionately on the wrist.

For the Datejust 31 in two-tone Rolesor construction (stainless steel and yellow gold), the most suitable straps are smooth-belly alligator in cognac or black for formal wear, or vegetable-tanned calf leather for everyday versatility. Shell cordovan is an excellent choice for those who appreciate the development of a rich patina over time. In all cases, the lug width must be 16 mm, and a deployant clasp is recommended to extend the life of any leather strap.

To replace the strap on the Datejust 31 178313-0041, you will need a spring bar tool to remove the spring bars securing the strap to the case lugs. Gently insert the forked tip of the tool against the spring bar collar, compress it towards the lug hole, and the bar will disengage. It is advisable to work on a soft surface to avoid scratching the steel and yellow gold case. The new 16 mm strap is fitted using the same process in reverse.

Yes, there are many aftermarket straps compatible with the Rolex Datejust 31 178313-0041, provided they have a 16 mm lug width. Milano Straps offers a curated selection of handcrafted leather, rubber, and NATO nylon straps in this specific size, with various clasp options — traditional tang buckle or deployant — and materials chosen to complement the yellow Rolesor construction of the case.

The longevity of a leather strap on a Rolex Datejust 31 depends on leather quality, maintenance, and frequency of use. A high-quality alligator or shell cordovan strap, properly maintained — rotated with other straps, treated with leather conditioner, and fitted with a deployant clasp to avoid mechanical stress — can last between 3 and 6 years. Plain calf leather straps typically have a shorter lifespan of 12 to 24 months with daily wear. Casati Milano's production warranty covers manufacturing defects for 18 months.