A. Lange & Söhne
1815 823.042— lug 20mm

The lug width of the A. Lange & Söhne 1815 Chronograph reference 823.042 is 20 millimetres. This measurement is taken from the base of the spring bar tube on one lug to the corresponding point on the opposite lug, measured on the inside of the case. With a case diameter of 39.50 millimetres, the 20mm lug width maintains balanced proportions on the wrist, avoiding both the "wings" effect and excessive tightness.

The optimal pairing for the 823.042 is alligator with vegetable tanning: the fine grain and regular texture convey restraint and discreet luxury that dialogues perfectly with the white gold case. Alternatively, calf leather with aged patina offers more pronounced character and natural colour evolution over time. Shell cordovan, though rarer, guarantees superior mechanical resistance and lacquer-like patina development with age. All these materials maintain the aesthetic and mechanical integrity expected from a chronograph of this calibre.

Changing the strap on an A. Lange & Söhne 1815 requires care to avoid scratching the bezel or case. Rest the watch on a soft surface (microfibre cloth). Locate the spring bar tubes at the lug terminals and use a dedicated spring bar tool to depress the tube inward, releasing tension. The old strap withdraws horizontally. Insert the new strap, ensuring the tubes click into their seats properly. Never use pointed instruments that could scratch; if uncertain, entrust the task to a watchmaker or Casati Milano's bespoke service.

Yes, any strap with a 20mm lug width is compatible with the A. Lange & Söhne 1815 823.042, provided it is manufactured to precise tolerances. Milanostraps.it offers a collection of 20mm straps in alligator, vegetable-tanned calf, shell cordovan and other materials, all dimensioned to ensure correct fit without case scarring. Casati Milano also produces bespoke personalised straps: consult the online catalogue or book the Milan atelier to personally select leather and colour.

A leather strap manufactured with vegetable tanning and quality materials (alligator, calf, shell cordovan) has an average lifespan of 4–6 years of constant daily wear, with variability dependent on climate, body perspiration and maintenance. Sun exposure accelerates ageing; warm and humid climates increase mechanical stress. Casati Milano straps benefit from an 18-month warranty on manufacturing defects. To extend useful life, occasionally apply natural conditioning balm and avoid prolonged water immersion. The colour patina that develops over time is not deterioration but character.