Rolex
Datejust 31 278344rbr-0022— lug 16mm

The Rolex Datejust 31, reference 278344rbr-0022, features a lug width of 16mm. This measurement, also referred to as lug width or attachment width, defines the distance between the case lugs where the strap attaches. Accurate measurement using a digital calliper is essential, positioning the tool at the inner base of the lug where the strap contacts the case. Incorrect measurement will result in strap incompatibility or poor fit.

Tinted alligator leather is the most refined choice for the two-tone Datejust 31. The natural scale pattern creates a harmonious dialogue with the white gold and steel combination. Excellent alternatives include vegetable-tanned calf leather, which develops patina over time, and shell cordovan, offering structural rigidity and natural lustre. For casual contexts, FKM rubber or NATO fabric provides versatility whilst maintaining elegance.

The Datejust 31 typically uses standard spring bars for strap attachment. To change the strap: 1) Obtain a proper spring bar tool. 2) Position the tool on the lower shoulder of the lug spring. 3) Gently push inward to compress the spring. 4) Remove the old strap. 5) Insert the new strap, ensuring both ends of the spring seat fully in the lug recesses. If unfamiliar with the procedure, consult an authorised watchmaker to avoid case damage.

Any strap with a 16mm lug width is compatible with the Datejust 31 278344rbr-0022. Milano Straps curates a selection of artisanal 16mm straps crafted by Casati Milano using premium hides: alligator, vegetable-tanned calf, and shell cordovan. Verification that the strap measures exactly 16mm at the attachment point is essential for correct fit and secure fastening to the case lugs.

Leather strap longevity depends on material quality, usage frequency, and environmental humidity. Premium straps—alligator or shell cordovan with vegetable tanning—typically last 3–5 years with daily wear. Tinted calf generally lasts 2–3 years. Casati Milano straps include an 18-month warranty against manufacturing defects. Prolonged exposure to moisture and perspiration accelerates deterioration; regular maintenance with specialised leather conditioners significantly extends strap life.