Historically used in ships and diving equipment, bronze has in recent years made a splash as a distinctive case material for diving watches (or at least, watches associated with all things aquatic). Notable examples include Panerai’s 2011 big hit, the Luminor Submersible 1950 Bronzo (PAM 382) and IWC’s Aquatimer Chronograph Edition “Expedition Charles Darwin” from 2014.
This year, the material resurfaces as the covering for an updated Tudor favourite: the Heritage Black Bay Bronze, a 43mm novelty powered by the new in-house automatic movement MT5601. The material’s most interesting property is that is that it can acquire a brownish copper oxide superficial layer, which helps to protect it against corrosion and gives it a unique patina over time. This patination will vary with factors such as the extent of the watch’s exposure to the elements: Think of it as a form of personalisation that’s truly unique to you.
Not all bronze, however, is the same. Bronze is an alloy primarily composed of copper, and the secondary metal can be tin (creating CuSn8), or aluminium (aluminium bronze). The Black Bay uses aluminium bronze, which its makers say will develop a “subtle” and “homogenous” patina. The latter quality is especially important – after all, what you want is a watch with personality, not patchy spots.