Grand Seiko · Mechanical

Strap for Automatic Date Titanium / Silver / 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 diameter38 mm
ReferenceSBGR259
FamilyMechanical
MovementGrand Seiko caliber 9S65 Hours, Minutes, Seconds | Date
CaseTitanium

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 SBGR259

Selected for the 20 mm lug width · workshop selection

All 20 mm straps →

The Mechanical SBGR259, seen from the bench

The Grand Seiko Mechanical SBGR259 is a 37.8mm titanium watch featuring the manual-wind Grand Seiko 9S65 caliber with Spron regulating system, ensuring chronometric accuracy within 15 seconds per day. The lug width is 20mm. This model combines minimalist Scandinavian design aesthetics with Japanese precision engineering, utilizing titanium for reduced wrist weight while maintaining structural rigidity to protect the movement.

Frequently asked questions

What is the lug width of the Grand Seiko Mechanical SBGR259?

The lug width of the Grand Seiko SBGR259 is 20 millimetres. This measurement represents the internal distance between the two metal pins (spring bars) to which the strap attaches. To verify this dimension accurately, use a digital calliper and measure the space between the case lugs after removing the original strap.

Which strap material is most suitable for the Grand Seiko SBGR259?

For the SBGR259, an alligator strap in dark brown or a shell cordovan option represents the ideal choice from both aesthetic and tactile perspectives. These materials respect the minimalist purity of the titanium case without introducing visually competing elements. For robust daily use, vegetable-tanned calf leather offers balanced durability. FKM rubber is recommended exclusively in maritime or high-humidity environments.

How do I change the strap on the Grand Seiko SBGR259?

Strap replacement requires the removal of the spring bars—the metal pins connecting the strap to the case. Using a dedicated spring bar tool or a small flat-head screwdriver, apply gentle pressure to release each pin from its housing, then remove the old strap. Subsequently, position the new 20mm strap and reinsert the spring bars until they fully engage. Never force: any unusual resistance indicates misalignment.

Are aftermarket straps compatible with the SBGR259?

Yes, any strap with a 20mm lug width is compatible with the SBGR259, provided the lugs are correctly constructed and the spring bars engage without play. Milano Straps' artisanal straps are specifically manufactured to Japanese manufacturing tolerances and guarantee perfect compatibility. It is essential to verify that the new strap does not present tolerances below 19mm or above 21mm, otherwise installation difficulties will occur.

How long does a leather strap last on the Grand Seiko SBGR259?

A leather strap's lifespan depends on material quality and usage patterns. A vegetable-tanned alligator strap, if properly maintained, can last 3–5 years of daily wear whilst developing a desirable patina. Shell cordovan exhibits superior longevity (5–7 years) due to the natural fibre resilience. Classic calf leather has a cycle of 2–4 years. Exposure to perspiration, fresh water, UV radiation and heat accelerates ageing. Rotating periodically between two straps significantly extends the longevity of both.

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