Grand Seiko · Mechanical

Strap for Automatic Hi Beat 36000 GMT Stainless Steel / Silver / Strap

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

Lug width20 mm
ReferenceSBGJ217
FamilyMechanical
MovementGrand Seiko caliber 9S86 Hours, Minutes, Additional 24 Hour Hand (adjustable), 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 SBGJ217

Selected for the 20 mm lug width · workshop selection

All 20 mm straps →

The Mechanical SBGJ217, seen from the bench

The Grand Seiko Mechanical SBGJ217 is a stainless steel timepiece with a 93.50 mm case diameter and 20 mm lug width, presented in 2017 for the brand's 60th anniversary. Powered by the Grand Seiko caliber 9S86, a high-beat automatic movement at 36,000 vibrations per hour, it features hours, minutes, seconds, a 24-hour GMT hand, and date display. The faceted case and Zaratsu polished finish exemplify Japanese watchmaking precision and construction rigor.

Frequently asked questions

What is the lug width of the Grand Seiko Mechanical SBGJ217?

The Grand Seiko Mechanical SBGJ217 features a 20 mm lug width. This dimension allows the timepiece to be paired with a wide range of artisanal straps, both ready-made and bespoke. To verify the lug width, insert a ruler between the two inner holes of the lugs and measure the perpendicular distance: the result should be exactly 20 mm.

What is the best aftermarket strap for the SBGJ217?

The choice depends on your intended use. For formal wear, we recommend vegetable-tanned calf leather in dark brown or black tones: it guarantees durability and develops a natural patina over time. For those seeking longevity exceeding 15–20 years, shell cordovan is the definitive solution. For sportier applications, silk-blend NATO straps maintain the aesthetic integrity of the SBGJ217 without functional compromise.

How do you change the strap on the Grand Seiko Mechanical SBGJ217?

Changing the strap requires extraction of the spring bars (or pins) that connect the strap to the watch lugs. Use a specialized tool such as a spring bar removal tool, or consult a qualified watchmaker. Ensure that the new strap has matching lug dimensions: 20 mm. Insertion of spring bars into the new strap must be performed carefully to avoid damage.

Is the SBGJ217 compatible with genuine alligator straps?

Yes, the Grand Seiko Mechanical SBGJ217 is fully compatible with genuine alligator straps measuring 20 mm. Genuine alligator offers a natural granular texture that dialogues elegantly with the faceted steel case. We recommend alligator of elevated construction quality, vegetable-tanned, to guarantee durability exceeding 10 years and the development of a rich patina over time.

How long does a leather strap last on the SBGJ217?

The lifespan of a leather strap depends on the material, tanning method, and wear patterns. A vegetable-tanned calf leather strap typically lasts 5–8 years under daily use. Shell cordovan, being leather extracted from the horse's back and possessing extraordinary resilience, can last 15–20 years or more. Vegetable tanning, furthermore, slows the ageing of leather compared to synthetic tanning methods, extending the functional life of the strap by up to 30 percent.

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