IWC · Pilot

Strap for Pilot's Watch Doppelchronograph Stainless Steel / Black / French / Strap

Takes 21 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.

Lug width

21mm
Lug width21 mm
Case diameter42 mm
ReferenceIW3713-08 (aka: IW371308)
FamilyPilot
MovementIWC caliber 79230 Hours, Minutes, Small Seconds | Date, Day | Chronograph, Rattrapante
CaseStainless Steel

Spring bar

Swiss Standard universal spring bars

The right category for this model · 316L steel, all lug widths 13–26 mm

Straps for the Pilot IW3713-08 (aka: IW371308)

Selected for the 21 mm lug width · workshop selection

All 21 mm straps →

The Pilot IW3713-08 (aka: IW371308), seen from the bench

The IWC Pilot ref. IW371308 mounts the caliber 79230 with split-seconds chronograph functions, hours, minutes, small seconds, date, and day. The watch features 21mm lugs and a split-seconds chronograph mechanism for intermediate time measurements. The movement offers an indication of the day of the week in addition to the traditional chronograph functions.

Frequently asked questions

What is the lug width of the IWC Pilot IW3713-08?

The lug width of the IWC Pilot IW3713-08 is 21 mm. This is an unusual size, not standardised like the common 20 mm or 22 mm widths. To verify accurately, measure the perpendicular distance between the two spring bars located at the sides of the case. This precision is essential to ensure a proper strap fit.

Which strap is recommended for the IWC Pilot IW3713-08?

For the Pilot IW3713-08, we recommend materials that respect the austere aviatic character of the watch: alligator with regular grain in mud brown or black tones, vegetable-tanned calf leather that ages visibly over time, or shell cordovan for those seeking greater elegance. For sport applications, a rubber or NATO strap preserves the original aviatic functionality. At milanostraps.it, you will find 21 mm straps customisable in colour, initials, and stitching thread.

How do I change the strap on this watch?

The Pilot IW3713-08 uses standard spring bars. To change the strap, use a spring bar tool or fine ballpoint pen: insert the tool into one of the small holes at the ends of the bar, press gently to compress the internal spring, and remove the lug from the case. Work carefully to avoid scratching the steel case. Repeat on the other side, then insert the new strap by seating the spring bars in their sockets.

Can I use a standard 21mm generic aftermarket strap?

Yes, any strap with a 21 mm lug width is mechanically compatible. However, we recommend choosing artisanal straps that respect the proportions and aviatic character of the Pilot. Generic commercial straps often feature poor finishing or incongruous thicknesses. The Casati Milano atelier and straps curated on milanostraps.it guarantee construction quality, noble leather, and sartorial details.

How long does a leather strap last on this watch?

Durability depends on leather quality and usage patterns. A quality alligator or shell cordovan strap typically lasts 5–7 years with daily wear. Vegetable-tanned calf leather has similar longevity, but patina becomes visible within 6–12 months. Rubber lasts approximately 3–4 years before degradation. Ageing is not a flaw but character: Casati Milano straps maintain 18-month warranty on materials and stitching, covering any manufacturing defects.

The next step

The right strap isn't chosen. It is built, together.

From the atelier appointment to delivery, every step is made for those who know that things done well take time. Rare leathers, one piece at a time, eighteen months of warranty.

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Casati Milano · Via XX Settembre 15, Milan · by appointment only