Thermite-carbon cord

Thermite-Carbon Cord is a type of incendiary device used by the UNSC. It consists of a long wire of unknown type with a charge. Once the charge is activated, a large amount of heat energy is released, and the subsequent burst of heat is capable of enormous amounts of anti-material damage, melting through solid metal.

The SPARTAN-III Beta Company used Thermite-Carbon Cords during Operation: TORPEDO. Tom-B292, used it to destroy the dump valve for a reactor of a Covenant facility. .

Conjecture
thermite is composed of iron-oxide and aluminum
 * It is possible that the Cord's charge is thermite (hence the name) and will thus burn at a very high temperature.