Grand Seiko · Mechanical

Strap for Automatic Date Stainless Steel / White / Bracelet

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

Lug width20 mm
Case diameter39 mm
ReferenceSBGR255
FamilyMechanical
MovementGrand Seiko caliber 9S65 Hours, Minutes, Seconds | Date
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 Mechanical SBGR255

Selected for the 20 mm lug width · workshop selection

All 20 mm straps →

The Mechanical SBGR255, seen from the bench

The Grand Seiko Mechanical SBGR255 is a 39.40mm stainless steel automatic watch with the caliber 9S65 movement, offering date function, 72-hour power reserve, and 100m water resistance. It features a sapphire crystal with anti-reflective coating and a 20mm lug width, representing the classical standard for cases of this diameter.

Frequently asked questions

What is the lug width of the Grand Seiko Mechanical SBGR255?

The lug width of the Grand Seiko Mechanical SBGR255 is 20mm, the classic standard for cases measuring 39-40mm. This width ensures balanced proportions between the strap and case. To verify correctly, measure the distance between the two metal lugs (projections) from the inside: the result must be exactly 20mm. Any measurement error would compromise both aesthetics and functionality of the watch.

Which strap is recommended for the Grand Seiko Mechanical SBGR255?

For the SBGR255, straps are recommended that age with dignity and respect the watch's essential design philosophy. Genuine alligator offers natural texture and develops rich patina over time. Vegetable-tanned calf leather aligns with classical aesthetics. NATO straps in dense cotton provide daily versatility. Fluoroelastomer rubber suits humid environments. Your choice depends on lifestyle and daily usage conditions. Quality construction is paramount on a timepiece of this calibre.

How do I change the strap on my Grand Seiko SBGR255?

Strap replacement requires a dedicated spring bar tool to extract the pins connecting the strap to the lugs. Position the watch on a soft surface to prevent scratches. Insert the tool's tip under the pin from one side, gently lift, then slide the strap outward. Repeat on the opposite side. To install the new strap, align the holes and reinserve the pins until you hear a click. If uncertain, consult a professional watchmaker for proper installation.

Can I fit aftermarket straps to my Grand Seiko SBGR255?

Yes, you can install aftermarket straps of 20mm lug width on the SBGR255. However, material quality and construction must be carefully considered: inferior straps compromise the aesthetics and functionality of a high-end timepiece. We recommend artisanal leather straps in premium quality, genuine alligator or cordovan, avoiding synthetic imitations. The Casati Milano atelier provides specialised advice and bespoke strap creation to ensure ideal pairing.

How long does a leather strap last on the Grand Seiko SBGR255?

Leather strap longevity depends on material quality, tanning method and daily usage. A premium alligator or shell cordovan strap can last 4-6 years of regular wear, developing desirable patina. Quality calf leather has similar durability. Fluoroelastomer rubber lasts longer (7-10 years) but lacks the ageing character. Critical factors: avoid prolonged water exposure, protect from intense UV rays, and rotate straps to distribute wear. Proper care extends lifespan significantly.

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