Strap for Series 556 I

The lug width of the Sinn 556.010 is precisely 20 mm. This is a non-standard dimension in the broader watchmaking market, requiring careful attention when selecting compatible straps. Correct measurement is performed by positioning a digital calliper between the two inner central lug pins, excluding the material of the lugs themselves.

Being a functional and minimalist instrument, the 556.010 harmonises perfectly with alligator or vegetable-tanned leather straps, which offer natural patina and aesthetic restraint. For operational use, NATO straps in heavy cotton or vulcanised FKM rubber maintain fidelity to its avionic heritage. High-polished finishes and precious metals are discouraged.

The strap is replaced by removing the spring bars using a dedicated tool: a spring bar tool or extraction device. Position the tool beneath the bar, applying gentle downward pressure to compress the internal spring, then extract the bar. Slide the old strap from the lugs and insert the new one, aligning the holes with the bars and ensuring the bar clicks into a locked position.

Yes, aftermarket straps may be used provided they correspond precisely to a 20 mm lug width. Artisanal straps, manufactured to equivalent structural quality standards, guarantee compatibility and often superior aesthetic flexibility. We recommend verifying the maker's reputation and stitch warranty prior to purchase.

A high-quality vegetable-tanned leather strap, under normal use (5–7 days weekly), maintains structural and aesthetic integrity for 18–30 months on average. Longevity depends on intensity of use, climatic conditions (humidity accelerates wear), and leather quality itself. Vegetable-tanned calf develops attractive patina before requiring replacement, whilst shell cordovan demands periodic maintenance but guarantees greater longevity.