Strap for Tangente Liebreiz / Open Case Back

The lug width of the Tangente 139.S51 is 18 millimetres. This dimension is measured from the centre of one lug to the inside of the other and is essential for selecting compatible straps. Use exclusively 18mm straps to avoid insertion issues and preserve case integrity.

Four solutions are recommended for the Tangente 139.S51: (1) alligator with vegetable tanning for formal elegance and evolving patina; (2) structured calf for durability and water resistance; (3) NATO nylon for practicality and daily versatility; (4) FKM rubber for complete water protection and easy maintenance. The choice depends on intended use and wear context.

Strap changes require precision tools (spring bar tool or dedicated removal tool). Locate the two lateral pins securing the strap to the lugs, gently extract them by pushing from one side to the other, then remove the worn strap. Insert the new strap by aligning the lateral holes and reinserting the pins, verifying they are perfectly positioned. Avoid hammers or improvised tools that could damage the lugs.

Yes, 18mm aftermarket straps are fully compatible with the Tangente 35. Milanostraps offers a specialised collection of artisanal 18mm straps, crafted with premium materials (alligator, calf, NATO, rubber) and designed for German horology. Compatibility is guaranteed, as are construction quality and proportioning suited to the case's compact dimensions.

Durability depends on material and wear frequency. An alligator strap with vegetable tanning, worn daily, has a useful life of 4–6 years before restoration becomes necessary. Structured calf resists 5–8 years. NATO and rubber straps have similar lifespans but more gradual and visually subtle deterioration. Proper maintenance—avoiding prolonged moisture, regular cleaning, protecting against scratches—significantly extends longevity.