Titanium-A armor

Titanium-A Armor is the most common hull plating used by the UNSC. It is high-grade titanium alloy that is usually greyish in color. This can not be pure titanium because titanium is the only known metal while in pure form that burns with nitrogen. Titanium-A has numerous uses throughout the UNSC. This is due largely to titanium's properties; it is a light and extremely strong metal with a high tolerance for heat. It took newfound importance after the beginning of the Human-Covenant War. To contend with the Covenant's plasma weaponry, humans needed armor that would withstand the heat.

Its primary use is as ship plating. UNSC Frigates have sixty centimeters of plating on their hull, and UNSC Destroyers have two meters of it. The Tralfagar had 10 meters. Marines sometimes have Titanium-A armor suits, though these are increasingly becoming a rare sight.

Titanium-A is also used in the construction of UNSC probes because the rough transition into Slipspace demands a strong and durable alloy that will not break under the pressure, meaning that they are made almost entirely out of it.

The UNSC uses Titanium-A for construction of bases as well, to make them less suceptible to destruction. Places such as HIGHCOM Facility Bravo-6, CASTLE Base, and Camp Hathcock use Titanium-A armor in their superstructures.