Nomos Glashütte Tangomat Ruthenium Ref. 603

The NOMOS Tangomat ruthenium 603 debuted in 2005 as the dark-dial version of the automatic Tangomat, originally powered by the Epsilon movement. The reference has since been updated to the DUW 5001 calibre, while retaining the 38.3mm stainless steel case, sapphire crystal case back, and Tangente-derived dial architecture of the Tangomat line. Its main visual distinction is the galvanized, ruthenium-plated dial, which gives the watch a darker and more metallic appearance than the white silver-plated Tangomat references. The stainless steel case measures 38.3mm in diameter, 8.3mm in height, and 48.0mm from lug to lug. It is fixed with six screws and fitted with sapphire crystal glass on the front and back. Water resistance is rated at 3 atm, making the watch splash-proof. Compared with the Tangente, the Tangomat has a larger and slightly taller case, with more pronounced angular lugs and the additional depth required by its automatic movement. The dial is galvanized and ruthenium-plated, using a metal from the platinum group to create a dark grey surface with a more reflective character than a matte black dial. Its layout follows the Tangomat format, with Arabic numerals, baton hour markers, a railway minute track, and a small seconds display at 6 o’clock. The polished and rhodium-plated hands provide contrast against the darker dial surface, while the overall layout remains closely related to the Tangente. Inside is the NOMOS Epsilon, an in-house automatic movement that supersedes the Epsilon calibre used when this reference first appeared. It measures 4.3mm in height, has a diameter of 31.0mm, and offers a power reserve of up to 43 hours. The movement is visible through the sapphire crystal case back. The watch is fitted to a black Horween Genuine Shell Cordovan strap with a 20mm lug width.