Strap for Speedmaster Broad Arrow Yellow Gold / Enamel

The lug width of the 3656.20.31 is exactly 20mm. This measurement must be verified by measuring the horizontal space between the spring bar pins that hold the strap in position. Purchasing straps of different sizes—for example 19mm or 21mm—compromises both the fit and aesthetic proportion of the watch. The 20mm specification is calibrated specifically for this chronograph model.

Alligator remains the most elegant choice and perfectly cohesive with yellow gold: the regular scales and defined grain create a refined contrast. Alternatively, shell cordovan (equine shell leather) offers a natural patina that ages beautifully, while vegetable-tanned calf provides sustainability and the ability to develop a noble patina over time. For sporty use, a neutral NATO fabric strap maintains functionality without compromising the elegance of the precious case.

The strap is changed using the spring bar pins located at the ends of the case. Remove the previous strap by gently pushing the pin from underneath with a dedicated tool or fine-tipped pen. Insert the new strap by aligning the holes with the pins, then press the pin until it clicks into position. Ensure that the lug width is correct (20mm for the 3656.20.31) and that the strap is positioned symmetrically. If unsure, the Casati Milano atelier can assist with the operation.

Yes, 20mm aftermarket straps are perfectly compatible with the 3656.20.31. Milanostraps.it offers an extensive selection of handcrafted straps in alligator, shell cordovan, calf, and technical materials, all available with 20mm lug width. Compatibility is guaranteed by the standard spring bar pins; what determines quality is the material, stitching, and attention to construction details. A well-made aftermarket strap can significantly elevate your daily wearing experience.

Durability depends on the material, frequency of wear, and environmental conditions. A high-quality alligator strap, worn daily, typically lasts 3-5 years before requiring replacement. Shell cordovan tends to last longer (5-7 years) thanks to fiber density, while vegetable-tanned calf offers 2-4 years of service. Exposure to humidity, excessive heat, and perspiration reduces longevity. Milanostraps and Casati Milano provide 18-month warranties on handcrafted straps, covering construction defects.