Nivada Grenchen
Antarctic 35004M16— lug 18mm

The lug width of the Nivada Grenchen Antarctic 35004M16 is precisely 18 millimetres. This measurement must be verified by placing a caliper on the internal width of the lug, excluding any spring bars or fastening elements. An 18mm strap fits the lugs with minimal construction tolerance, allowing slight rotation that reduces torsional stress on the attachment point.

For the 35004M16, we recommend alligator straps in black or dark brown for formal wear that harmonises with the octagonal case geometry, or vegetable-tanned calf leather for collectors seeking a patina that evolves with time. Alternatively, a heavy cotton NATO strap or fluoroelastomeric (FKM) rubber for sports contexts. The fundamental rule is that the strap must never compete chromatically with the dial.

Strap change requires a specific tool called a spring bar tool. Position the watch face-down, insert the tool into the space between the case and the existing strap to compress the internal spring bar, and slide the strap outward. Repeat on the opposite side. Installing the new strap follows the reverse procedure, ensuring the spring bar is fully seated within both lugs.

Yes, any strap with an 18mm lug width is mechanically compatible with the 35004M16. We recommend verifying that strap thickness does not exceed 3.5–4mm at the contact point with the case, to prevent friction against the crown guard. High-quality artisanal leather straps also adapt both aesthetic and durability standards to match the value of the Landeron movement.

Durability depends on material and usage pattern. A high-quality alligator or vegetable-tanned calf strap typically lasts 3–5 years with daily wear, developing pleasant patina. Shell cordovan straps can last 7–10 years. FKM rubber typically lasts 4–6 years. Longevity increases significantly if the strap is regularly cleaned, protected from direct sunlight, and the watch is stored in a dry environment.