Omega · Speedmaster Broad Arrow

Strap for Speedmaster Broad Arrow White Gold / Enamel

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
Reference3657.20.31
FamilySpeedmaster Broad Arrow
MovementOmega caliber 3320 hours, minutes, small seconds | date | Chronograph, column wheel
Year2002 - 2004
CaseWhite Gold

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 Broad Arrow 3657.20.31

Selected for the 20 mm lug width · workshop selection

All 20 mm straps →

The Speedmaster Broad Arrow 3657.20.31, seen from the bench

The Speedmaster Broad Arrow reference 3657.20.31 is equipped with the Omega 3320 automatic caliber with column-wheel chronograph function. The movement indicates hours, minutes, small seconds and date. The watch features 20mm lugs for the strap.

Frequently asked questions

What is the lug width of the Omega Speedmaster Broad Arrow 3657.20.31?

The lug width of the 3657.20.31 is 20.00mm, a non-standard measurement that requires targeted research. The width must be measured with millimeter precision in the inner lugs of the case, as even small variations can cause play or friction during wear.

What is the best strap for the 3657.20.31?

Alligator leather (vegetable tanning) represents the most coherent choice with the elegance of white gold and the nature of the chronograph. For versatility, shell cordovan offers superior mechanical resistance and natural patina that evolves over time. For daily sportive wear, vegetable-tanned calf leather provides an excellent balance between aesthetics and practicality.

How do I change the strap on my Speedmaster Broad Arrow?

Strap replacement requires the use of appropriate tools (spring bar removers or thin-blade screwdrivers) to extract the pins from the lugs. Insert the pin into the new strap by correctly positioning the ring in its seat, ensuring that the lugs adhere perfectly to the case. For critical operations on chronographs, it is advisable to contact an authorized Omega service center.

Can I use third-party aftermarket straps on my 3657.20.31?

Yes, you can use aftermarket straps compatible with the 20mm lug width, provided they are manufactured to precision standards. High-quality artisanal straps guarantee certified compatibility and allow customizations (leather, color, stitching thread) not available in the standard market.

How long does a leather strap last on this watch?

Durability depends on the material: alligator and shell cordovan guarantee 3-5 years with daily use; simple calf leather 2-3 years. The frequency of strap changes affects the longevity of the product. With correct <a href="/pages/termine-glossario/concia-vegetale">vegetable tanning</a>, the leather develops natural patina rather than degrading, extending the period of conscious use.

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