Strap for Speedmaster Date 39 Stainless Steel / Black

The lug width is 18 millimetres, measured inner-to-inner between the two case lugs. It is a specific and non-standard measurement, so it is essential to verify it with a digital calliper before ordering any aftermarket strap.

Alligator is recommended for those who want to emphasise the racing character; shell cordovan offers constructive longevity and natural patina over time; full-grain calf guarantees personalised aesthetic development. For sports use, NATO or satin rubber are the functional choices.

Use a spring bar tool to gently compress the elastic pins (spring bars) that secure the strap to the lugs. Apply uniform pressure from both sides, remove the worn strap and insert the new one ensuring that the pins click fully into the holes. Avoid hammering or excessive pressure that could damage the pins.

All straps with 18mm lug width are compatible, provided that the leather thickness does not exceed 2.5-2.8mm (to avoid difficulty in lug passage). Choose suppliers that guarantee certified technical compatibility and offer warranty against manufacturing defects.

A quality full-grain calf strap, with proper maintenance (periodic cleaning and conditioning), typically lasts 3-5 years of daily wear. Shell cordovan, due to its superior density, can reach 7-10 years. Wear is mainly visible on the inner edge and on the buckle passage area.