Strap for Perpetual Calendar Split-Seconds Chronograph 5951P Black / Silver

The lug width is 20mm. This dimension is the standard for medium-to-large format watches and is easily verified by measuring the distance between the two strap attachment pins on the case. For the 5951P-001, this size ensures balanced proportions between the 37mm diameter and the overall visual mass of the platinum case.

For a watch of this complexity and value, alligator (true crocodile) remains the most noble and appropriate solution. The natural grain of the reptile pairs perfectly with the platinum case patina. Alternatively, vegetable-tanned calf offers sartorial elegance with a patina that evolves over time, or shell cordovan for those preferring a formal yet less austere option.

The change requires a specific spring bar tool and calibrated pressure. Position the tool beneath the attachment pin (lug) and apply smooth, constant pressure until the bar detaches. Avoid sharp impacts or excessive twisting that could damage the seatings. We recommend consulting a specialist watchmaker to ensure precision and case protection.

Yes. An aftermarket 20mm strap is fully compatible. What matters is construction quality and finishing level: for a Patek Philippe in this category, noble leather (alligator, calf, shell cordovan) with hand-sewn seams is the minimum acceptable standard. Casati Milano creates custom straps respecting the highest sartorial standards.

A quality leather strap (alligator or calf) with appropriate tanning typically lasts 4–6 years of daily wear. Longevity depends on UV exposure, humidity, frequency of use, and maintenance care. Leather treated regularly with watch-specific balms extends lifespan significantly. Casati Milano straps include an 18-month warranty against manufacturing defects.