Strap for Black Bay 39 S&G - Diamond / Black - Diamond / Bracelet

The lug width of the Tudor Black Bay One 79673-0005 is 20 millimetres. This dimension is measured between the inner shoulders of the metal pins (spring bars) that connect the case to the watch strap lugs. It is essential to verify this measurement before purchasing an aftermarket strap, as any different width (18mm or 22mm) would result in complete incompatibility.

For the two-tone Tudor, polished alligator represents the most refined choice, amplifying the warmth of the yellow gold with tightly-grained leather. Vegetable-tanned calf leather (in shades of havana, cognac, or honey brown) develops a beautiful natural patina over time. Shell cordovan offers maximum sophistication, with its semi-glossy finish contrasting elegantly against the gold components. Not recommended: rubber and synthetic materials, which visually 'cheapen' the chromatic balance of the case.

The 79673-0005 features standard side-loading spring bars. Using a spring bar tool, apply gentle pressure to the internal spring of the lower lug to retract the pin, remove the old strap, and insert the new one whilst aligning it correctly with the case lugs. Ensure the pin is fully seated: it should click into position audibly. For greater confidence, entrust the operation to Casati Milano atelier, which performs the replacement with precision and final verification.

Yes, any strap featuring a 20mm lug width and standard spring bars is compatible. Milanostraps.it offers a curated selection of 20mm straps crafted by artisans, customisable in length, initials, and stitching thread colour. What matters is verifying that the strap has been manufactured specifically for this width and that the material quality is commensurate with the nobility of the case (avoid cheap plastics and economy synthetics).

A well-crafted leather strap (alligator, calf, shell cordovan) under regular wear typically lasts 3–5 years before replacement becomes necessary. Durability depends on usage intensity, climatic conditions, and maintenance (avoid prolonged moisture and direct sunlight exposure). Straps made from vegetable-tanned leather develop a natural patina that enhances aesthetic appeal with age. Casati Milano provides an 18-month warranty on all bespoke straps.