IWC
Pilot IW3713-25 (aka: IW371325)— lug 21mm

The lug width of the IWC Pilot IW3713-25 is 21mm. This intermediate measurement ensures proper visual proportion on the 42mm case. To verify strap compatibility, measure the distance between the lugs using a digital calliper: the value must correspond precisely to 21mm.

We recommend alligator with vegetable tanning, calf leather (grained or gummed) for the IW3713-25. Dark brown alligator (mahogany) provides elegant contrast against the brushed steel case, developing a golden patina over time. For severe use, natural rubber NBR offers waterproofness and zero maintenance, whilst military-grade canvas NATO emphasises the flight watch heritage.

Strap replacement requires a spring bar tool. Remove the current strap by accessing the lugs from both case ends. Grip the lug pin with the tool, apply gentle pressure and slide the strap outward. Insert the new strap, aligning the holes with the pins, then secure the pins in position. If you lack the tool, Casati Milano atelier provides replacement service by appointment.

Yes, provided the lug width is exactly 21mm. All straps in the milanostraps.it collection for 21mm are compatible with the IWC Pilot IW3713-25. The guaranteed leather quality and stitching ensure durability comparable to OEM straps, with added customisation options (wrist size, initials, thread colour).

Durability depends on material and usage. Vegetable-tanned alligator resists 3-5 years with moderate daily wear; gummed calf 2-3 years; shell cordovan 4-6 years due to its dense structure. NASA-style or NBR rubber straps do not age and last indefinitely. Casati Milano atelier includes 18 months warranty on all custom-made straps.