Technical Archive

Rolex
Datejust 31 178159-0021— lug 16mm

Rolex Datejust 31 178159-0021: 16mm strap. Alligator, box calf, shell cordovan and rubber, cut and stitched in Milano. Choose your leather.

Datejust 31 White Gold Diamond / President / Meteorite

Artisanal Note

"This model requires a precise 16mm lug width to preserve the original sartorial balance."

Technical Specifications

Rolex 178159-0021
Lug Width
16 mm

The essential strap measurement.

Browse 16mm straps →
Reference

178159-0021

Movement

Rolex caliber 2235 Hours, Minutes, Seconds | Date | Chronometer

The Heritage

The Rolex Datejust 31 White Gold Diamond, reference 178159-0021, is a 31mm case watch in 18kt white gold featuring the Rolex caliber 2235 automatic movement with COSC chronometer certification. The Oyster case provides 100-meter water resistance through the Twinlock crown and Oyster case back, while the sapphire crystal with bilateral anti-reflective coating ensures clarity. The lug width measures 16mm, distinct from the 20mm of the Datejust 41 or other family variants, and requires precise measurement before ordering a replacement strap.

FAQ

What is the lug width of the Rolex Datejust 31 reference 178159-0021?

The lug width of the Rolex Datejust 31 ref. 178159-0021 is 16mm. This measurement is taken on the inside of the lugs using a digital calliper placed at the spring bar attachment point. It should not be confused with the overall case width. Only the internal lug measurement determines strap compatibility.

What is the best strap for the Rolex Datejust 31 178159-0021?

For an 18kt white gold case such as that of the Datejust 31 178159-0021, a vegetable-tanned alligator strap is the most coherent choice for the dressy register of the watch. The symmetrical belly grain of alligator leather complements the polished finish of white gold. Alternatively, shell cordovan in neutral tones — grey, burgundy, midnight blue — develops a refined patina over time. For casual wear, vulcanised rubber is technically appropriate and visually light.

How do you change the strap on a Rolex Datejust 31?

To replace the strap on a Rolex Datejust 31, a spring bar tool is required. Insert the forked tip into the lug hole, compress the spring bar and slide the strap free. Given the white gold case, it is advisable to use PTFE tape on the lugs to prevent scratching. If you are unfamiliar with the procedure, a watchmaker or a specialist atelier such as Casati Milano can carry out the swap safely.

Are there aftermarket straps compatible with the Rolex Datejust 31 178159-0021?

Yes, high-quality aftermarket straps compatible with the Rolex Datejust 31 178159-0021 are widely available. The standard 16mm lug width is supported by many independent craftsmen and specialist manufacturers. Milano Straps offers straps in alligator, shell cordovan, calfskin and rubber, made to order or selected for direct compatibility with this reference. Fitting an aftermarket strap does not affect the Rolex manufacturer's warranty, as no intervention on the movement is involved.

How long does a leather strap last on a Rolex Datejust 31?

The lifespan of a leather strap on a Rolex Datejust 31 depends on the material, tanning method and daily use. A vegetable-tanned alligator strap, kept away from water, perspiration and sunscreen, can last between three and five years with regular wear. Shell cordovan tends to last longer due to the dense, compact fibre structure. Milano Straps provides an 18-month guarantee against manufacturing defects. Rotating between two straps is recommended to extend the useful life of each.

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 →

By appointment only · Milan

The atelier's website: casatimilano.com