Strap for Master Collection Date 36 Stainless Steel Black

The lug width (strap attachment width) of the Longines Master Collection L2.518.4.51.6 is 19 millimetres. This measurement refers to the internal distance between the two horizontal pins that pass through the lateral lugs of the case. It is essential to verify this measurement before purchasing a compatible strap, as an undersized lug width creates excessive tension at the attachment points, whilst an oversized lug width results in looseness and uncontrolled movement.

For the L2.518.4.51.6, straps in vegetable-tanned alligator (for formal elegance and natural patina development), calf leather (for versatility and daily practicality), or shell cordovan (for durability and characteristic patina development) are recommended. The most harmonious colours are dark brown, black, and navy blue. The choice depends on the intended use: leather for formal occasions, rubber for sporting contexts.

To change the strap on the L2.518.4.51.6, you must remove the two horizontal pins that secure the strap to the case lugs using a spring bar removal tool. Position the tool on the upper side of the pin, press downward to compress the internal spring, and extract the pin. Repeat for the second pin. The operation requires care to avoid scratching the case. If you are not experienced, it is advisable to consult a professional watchmaker.

Yes, it is entirely possible to use an aftermarket strap provided it has the correct 19mm lug width. Artisanal straps often offer superior quality to Longines originals, allowing customisation in leather, colour, length, and details (buckle, stitching thread). Ensure that the strap is constructed with professional cutting and stitching techniques, and that it is tested for mechanical compatibility with the original pins.

The lifespan of a leather strap depends on leather quality, frequency of use, and maintenance. An artisanal strap in alligator or shell cordovan can last 5–8 years of regular use, whilst calf leather tends to wear more rapidly (3–5 years). Prolonged exposure to sunlight, moisture, and perspiration accelerates ageing. Proper maintenance (periodic cleaning and drying) and rotation between multiple straps significantly extends useful life.