Rolex · Datejust 31
Strap for Datejust 31 Rolesor Everose Domed Diamond / Jubilee / Black MOP Roman
Takes 16 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.
Lug width
Straps for the Datejust 31 178341-0027
Selected for the 16 mm lug width
The Datejust 31 178341-0027, seen from the bench
Frequently asked questions
What is the lug width of the Rolex Datejust 31 178341-0027?
The lug width of the Rolex Datejust 31 ref. 178341-0027 is 16 millimetres. This measurement represents the space between the case lugs and is specific to this reference. To measure correctly: use a digital calliper or ruler, positioning it perpendicular to the bridge between the two lugs at the point where the spring bar reaches maximum opening diameter. A strap with a lug width either below or above 16mm will not fit properly and will compromise both aesthetics and safety.
Which strap material best suits the Rolex Datejust 31 178341-0027 with mother-of-pearl dial?
For the 178341-0027 in Everose Rolesor with mother-of-pearl, we recommend three options: cognac or tobacco alligator, which creates elegant contrast with the rose tone of the gold and develops deep patina over time; shell cordovan, which develops mirror-like brilliance after three months of wear, harmonising with the dial's iridescence; Tuscan calf with pronounced grain, for those who appreciate rapid colour change and prefer a softer hand-feel. All these materials require certified vegetable tanning and result in unique patinas developed over years of wear.
How do I change the strap on my Rolex Datejust 31?
Strap change requires a spring bar tool (spring bar removal instrument). Procedure: place the watch on a flat surface, insert the flat tip of the spring bar tool into the small opening on the lug (where the spring emerges), gently lift until the spring retracts completely, and remove the strap from the case. Reverse the process to install the new strap. Advice: avoid harsh movements and do not apply excessive force to the lugs, which are delicate precious metal components. If uncertain, consult a professional watchmaker.
Can I use an aftermarket strap on my Datejust 31 178341-0027?
Yes, absolutely. Aftermarket straps with 16mm lug width are fully compatible with the 178341-0027. Indeed, the philosophy of quality aftermarket (such as Casati Milano) allows you to personalise your watch with materials and finishes impossible in the official Rolex catalogue. A bespoke strap in alligator, shell cordovan or vegetable-tanned calf, crafted using sartorial techniques, does not compromise the watch's value — rather it enhances it in the eyes of those who recognise artisanal quality. Simply verify that the lug width is exactly 16mm and that the spring bars are compatible (universal standard).
How long does a natural leather strap last on a daily-worn watch?
A vegetable-tanned leather strap worn daily and exposed to regular moisture (showering, perspiration, humid environments) typically maintains structural integrity between 3 and 7 years. Duration depends on: tanning quality (vegetable-tanned lasts longer than chrome-free), thickness of the raw hide (minimum 1.4mm), frequency of moisture and UV exposure, and maintenance (weekly cleaning with damp cloth, semi-annual lubrication with natural waxes). Shell cordovan, being denser, achieves 10+ years. Tuscan calf, being softer, may show wear after 4-5 years. Rotating between multiple straps extends the average lifespan of each, allowing materials to 'breathe' between wears.
The next step
The right strap isn't chosen. It is built, together.
From the atelier appointment to delivery, every step is made for those who know that things done well take time. Rare leathers, one piece at a time, eighteen months of warranty.
Request an appointment →Casati Milano · Via XX Settembre 15, Milan · by appointment only

