Strap for Datejust 31 Stainless Steel Domed Diamond / Oyster / Black - Roman

The lug width of the Rolex Datejust 31 178344-0013 is 16 millimetres. This measurement refers to the inner diameter of the lugs—the space between the internal edges of the two terminals where the strap inserts. Precise compatibility is essential: a 14 or 18 millimetre strap will not fit correctly and risks damaging both the watch lugs and the strap itself.

For the Datejust 31 178344-0013, polished alligator in ivory or cream-white tones emphasises the two-tone case's elegance. Grained calf in hazelnut or sand offers daily versatility whilst maintaining formal presence. Shell cordovan—horsehide with superior durability characteristics—suits the wearer seeking longevity and natural patina development over time. For sporting contexts, technical fabrics or vulcanised rubber convert the Datejust 31 into an informal daily companion without sacrificing refinement.

Strap replacement requires a spring bar tool, designed to compress the lug spring without scratching the case. Position the Datejust 31 at 3 and 9 o'clock, insert the tool into the lug slot, gently compress the spring and slide out the old strap. Insert the new strap (16mm width) in reverse, ensuring the terminals seat evenly. Work on a soft surface to prevent case scratches. If uncertain, consult a qualified watchmaker.

Yes, provided the aftermarket strap respects the 16 millimetre lug width specification and meets Rolex's construction tolerances. Straps in alligator, calf, shell cordovan or technical textiles from quality artisans (such as Casati Milano) are fully compatible and often offer aesthetic and material variety superior to OEM Rolex options. Always verify lug width before purchase to ensure proper fit.

Leather strap longevity depends on material type and usage intensity. Alligator, a noble leather with dense fibre structure, typically lasts 3–5 years of daily wear. Standard calf achieves 2–3 years. Shell cordovan, treated with vegetable tannins, can reach 5–7 years due to superior fibre density. Constant sun exposure, humidity and perspiration accelerate ageing. Proper maintenance—periodic cleaning, protective cream application and rotating between straps—significantly extends lifespan.