Strap for 1858 Automatic Chronograph Stainless Steel / Black / NATO

The lug width of the Montblanc 1858 Reference 117835 is exactly 20mm. This measurement represents the distance between the pins that support the strap, and is critical for proper installation. Always verify with a digital calliper before purchasing an aftermarket strap, positioning the measuring tool between the lug holes.

The Montblanc 1858 117835 pairs excellently with straps in natural alligator, calf leather with organic grain, NATO in cordura, and vulcanised rubber. The choice depends on use: alligator for formal occasions, NATO or rubber for technical activities, calf for an elegant everyday balance. All materials develop distinctive patina over time.

Strap change involves removing the pins that pass through the lugs, a task requiring a dedicated tool (spring bar pen or precision knife). Insert the new strap by aligning the passage holes with the lugs, then reinsert the pins from outside inward. Verify that the strap has no lateral play; if undersized, it will not mount correctly; if oversized, it will cause wear. Those preferring to avoid risk can use Casati Milano's bespoke fitting service by appointment.

Compatibility is guaranteed only if the strap is designed for a 20mm lug width and the passage holes are correctly dimensioned. However, true compatibility also includes aesthetic considerations: the keeper must adapt to the curve of the case and midline without creating tension. A quality artisanal strap, crafted to precise technical specifications, ensures optimal fitment and longevity.

A quality leather strap (alligator, calf, shell cordovan) on a tool watch like the 117835 typically lasts 3-5 years in daily use, depending on climate, perspiration and maintenance. Natural leather adapts to the wrist creating patina, but constant contact with humidity, salt and friction accelerates wear. Vulcanised rubber lasts longer (5-8 years) in humid or sporty environments. Timely replacement keeps the watch in excellent condition.