Rolex
Datejust 31 178383-0002— lug 16mm

The lug width of the Rolex Datejust 31 178383-0002 is 16 millimetres. This is the distance between the two attachment pins, measured perpendicularly. It is a specific dimension for the Datejust 31 with Oyster case and should not be confused with the case diameter itself (31mm). To verify the measurement correctly, use a digital calliper positioned between the attachment holes without applying excessive pressure.

The optimal strap choice depends on intended usage and aesthetic preferences. For formal and professional contexts, cognac or honey alligator, or shell cordovan, maintain the authority of the two-tone case. For a contemporary and versatile approach, vegetable-tanned calf leather develops a natural patina that testifies to the bond with the timepiece. Avoid straps that duplicate the gold colour; instead, opt for tones that create contrast (dark brown, taupe grey, burgundy). A stainless steel deployante buckle preserves the case balance.

To change the strap on the Datejust 31, you will need a spring bar tool (T-shaped or fork-shaped). Position the watch on a soft surface, locate the upper pin of the old strap, insert the tool tip into the slot and compress the spring gently. Repeat from the other side. Insert the new strap by passing the pins through the attachment holes, ensuring the spring clicks securely into position. If you lack experience, entrust the task to a specialist to avoid damage to the case.

Straps compatible with the 16mm lug width of the Datejust 31 178383-0002 include alligator, calf leather of any tanning method (vegetable, chrome, combination), shell cordovan, technical canvas and structured rubber. On milanostraps.it you will find a dedicated collection of 16mm straps, with artisanal options crafted bespoke at the Casati Milano atelier. Always verify that the strap has been sized for exactly 16mm: even half a millimetre of deviation compromises fit.

The lifespan of a leather strap varies according to tanning method, intensity of use and environmental conditions. Quality alligator can last 3–5 years with daily wear. Vegetable-tanned calf, more vulnerable to moisture, resists 2–4 years. Shell cordovan, thanks to its density, can exceed 5 years. Exposure to perspiration, water and sunlight accelerates ageing. Casati Milano straps include an 18-month warranty covering manufacturing defects; minor creasing and gradual discolouration fall within the natural patina of leather and are not covered.