Grand Seiko
Mechanical SBGR255— lug 20mm

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.

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.

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.

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.

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.