Strap for BC4 Chronograph Stainless Steel / Black

The lug width is precisely 22mm. This measurement represents the distance between the lugs of the case and determines which straps are compatible. Measure with a digital calliper to verify compatibility before purchasing, as even 1mm difference renders a strap incompatible.

For a technical pilot's watch like the BC4, we recommend Tuscan vegetable-tanned leather in Testa di Moro (dark brown), which creates an elegant contrast with the satin-brushed steel case. Alternatively, a double-layer canvas NATO strap offers practicality for marine or high-stress working environments. For collectors, alligator leather or shell cordovan represent long-term investments that develop character patina over time.

Insert a spring bar removal tool into the space between the lug and case, gently pushing downward to compress the spring pin. Once released, pull towards you and the lug will detach. Repeat on the other side, then insert the new strap onto both lugs and press until it clicks. Avoid excessive force to prevent damage to the stainless steel components.

Yes, numerous manufacturers offer 22mm-sized straps. Milano Straps provides dedicated collections for 22mm lugs in Italian vegetable-tanned leather, military NATO, structured rubber and exotic materials. It is essential to verify that the strap is certified 22mm and that the internal structure (channel for the spring bar) has standard diameter to avoid installation issues.

A quality vegetable-tanned leather strap, with regular maintenance, typically lasts 3-5 years under normal daily wear conditions. Factors such as humidity, perspiration, sun exposure and frequency of use affect longevity. Leather deteriorates more rapidly if untreated; applying mink oil or protective balm occasionally extends strap life significantly. Synthetic materials (NATO, rubber) have a lifespan of 5-7 years before showing visible wear.