Omega · Speedmaster Moonwatch

Strap for Speedmaster Professional Moonwatch 50th Anniversary

Takes 20 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.

Lug width20 mm
Case diameter42 mm
Reference311.30.42.30.01.001 (aka: 31130423001001)
FamilySpeedmaster Moonwatch
MovementOmega caliber 1861 Small Seconds, Hours, Minutes | Chronograph
CaseStainless Steel

Recommended spring bar

Spring bars Omega 20mm — 1.8mm diameter

Technical match for lug width and diameter · lug 20 mm · Ø 1.8 mm

All Omega spring barsOpen →

Straps for the Speedmaster Moonwatch 311.30.42.30.01.001 (aka: 31130423001001)

Selected for the 20 mm lug width · workshop selection

All 20 mm straps →

The Speedmaster Moonwatch 311.30.42.30.01.001 (aka: 31130423001001), seen from the bench

The Speedmaster Moonwatch was introduced in 1957 and represents the modern version of the chronograph used in the Apollo moon missions. It is equipped with the manual-winding Omega 1861 caliber with hour, minute, small seconds and chronograph functions. The case features 20mm lugs and maintains the classic proportions of the original model.

Frequently asked questions

What is the lug width of the Omega Speedmaster Professional 311.30.42.30.01.001?

The lug width is 20mm. This measurement corresponds to the distance between the pins that anchor the strap to the case lugs. It is the specific standard of the Speedmaster Professional and determines direct compatibility with aftermarket straps. The pins have a diameter of 1.8mm, compatible with standard spring bars.

Which strap pairs best with the Speedmaster Moonwatch 311.30.42?

Black anthracite alligator or deep burgundy shell cordovan represent the highest elegance choices. For historical authenticity, the NATO strap remains genuine. Vegetable-tanned calf leather offers the best balance between aesthetics, sustainability and durability, with lower investment compared to cordovan. The choice depends on intended use: daily wear, collecting or occasional.

How do you change the strap on an Omega Speedmaster?

The procedure is simple: position the watch on a stable surface, use a small tool to remove the pin from the case (proceed from one side to the other), then remove the old strap. Insert the new strap into the lugs and reinsert the pins, ensuring they are fully seated. No watchmaking expertise is required; however, Casati Milano provides consultative support for those who desire assistance.

Is there an aftermarket strap compatible with the 311.30.42.30.01.001?

Yes, any strap with 20mm lug width is compatible. On milanostraps.it you will find a complete range of artisanal straps in various leathers: alligator, shell cordovan, vegetable-tanned calf, FKM rubber, NATO. All are ready to ship and customizable in sizes, initials and stitching thread.

How long does a leather strap last on an Omega Speedmaster worn daily?

Durability depends on the material. Alligator and shell cordovan guarantee 48-60 months of intensive use, with a patina that improves over time. Vegetable-tanned calf: 36-48 months. Canvas NATO: 60+ months. FKM rubber: 48-72 months. Factors such as humidity, direct sunlight, and perspiration affect aging. Casati Milano provides an 18-month warranty on all custom-made straps.

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