Titanium enters watchmaking with a precise structural advantage: at equal volume, it weighs roughly 40% less than stainless steel and withstands higher loads. This strength-to-weight ratio makes it the reference material for sports cases, dive watches, and complications that must remain light on the wrist without yielding under stress.
Not all alloys are equal. Grade 2 is commercially pure titanium (approximately 99.8%): virtually no corrosion, excellent biocompatibility, but limited hardness and difficult machining. The surface doesn't polish like steel and remains decidedly matte, brushed, with an industrial appearance that brands like MING deliberately exploit. Grade 5, known as Ti-6Al-4V, introduces aluminum and vanadium: harder, easier to mill, better suited to mixed finishes. Grade 23 refines Grade 5 by reducing oxygen, nitrogen, and iron: Laventure uses it, Blancpain uses it in the Air Command, anywhere maximum fatigue resistance in saline environments is needed.
Titanium is naturally non-magnetic, a property Ressence actively leverages because the internal magnetic transmission of the case requires a container that doesn't interfere with the fields at play. For minute repeaters the discussion is acoustic: gold and platinum dampen sound waves through density, while titanium, low in density and rigid, amplifies both volume and duration of sound. Some cases are hollowed at the center precisely to create a resonance chamber.
Titanium surface finishes are a chapter unto themselves. PVD (Physical Vapor Deposition) deposits in vacuum a hard layer that protects and colorizes: stealth black, golden tones, dark gray variants. CVD (Chemical Vapor Deposition) works chemically and allows tones like blue on dials then reworked with laser. Thermal oxidation, developed by Denis Flageollet for De Bethune, generates colors like yellow directly on the oxidized layer, without additional coatings. TiDamas combines Grade 2 and Grade 5 with damascene technique: the two grades react differently to heat and produce iridescent patterns on the surface.
There exist composite materials that start from titanium and push it further. IWC's Ceratanium bakes a titanium alloy at high temperature until achieving ceramic hardness with a dark metallic finish. Citizen's Duratect TIC (Titanium Impact Coating) is a proprietary coating applied to the so-called Super Titanium to increase surface resistance. Crystallized titanium, rare in watchmaking, presents complex visual texture yet feels smooth to the touch: it's used on dials where depth is sought without physical relief.
From the bench: titanium scratches with less force than steel, but the scratches remain more opaque and less visible. Whoever wears a titanium watch without protective coating will find the surface marked quickly, but rarely disturbingly so.