IWC
Pilot IW3713-32 (aka: IW371332)— lug 21mm

The lug width of the IWC Pilot IW3713-32 is 21mm. This measurement is specific to this generation of Pilot and ensures visual balance with the 42mm case diameter. Measurement should be taken at the base of the lugs where the strap rests on the case.

For the Pilot IW3713-32 we recommend alligator (black or brown) for formal elegance, vegetable-tanned calf for chromatic evolution over time, NATO nylon ripstop for aviator authenticity, or FKM rubber for sports environments. Cognac-coloured alligator references the historical tradition of pilot watch straps.

The strap is changed using a spring bar removal tool. Position the forked end beneath the pin located at the base of the lug, push upward to compress the internal spring, then withdraw the strap from the case. Insert the new 21mm strap by aligning the holes with the lugs and press the pin until it clicks into place. For movement or case work, contact an authorised IWC service centre.

Yes, 21mm aftermarket straps are fully compatible with the IW3713-32 provided the width is precise. Artisanal straps from milanostraps.it made for the 21mm lug width guarantee correct retention and smooth buckle rotation. The Pilot's steel lugs are machined to tight tolerances, so we recommend verifying nominal width before purchase.

A high-quality alligator strap has a lifespan of 5–8 years under regular use (3–5 days weekly). Vegetable-tanned calf lasts 4–6 years but develops more visible patina over time. NATO nylon ripstop can last 8–10 years. Durability depends on use, ambient humidity, and maintenance. Casati Milano straps include 18-month warranty and can be refurbished or replaced at the atelier by appointment.