Bronze

Bronze is an metal alloy consisting primarily of copper, commonly with about 12–12.5% tin and often with the addition of other metals (such as aluminium, manganese, nickel or zinc) and sometimes non-metals or metalloids such as arsenic, phosphorus or silicon. These additions produce a range of alloys that may be harder than copper alone, or have other useful properties, such as stiffness, ductility, or machinability. As many metals in the Supernatural franchise, bronze has magical properties and can be used as a weapon in supernatural hunting, spells and rituals.

Sirens
One of the ways to kill a siren is using a bronze dagger coated in the blood of one of its victims.

Anubis
The Blade of Life Everlasting is a magical bronze dagger used in the Rite of Renewal, a ritual dedicated to Anubis to keep him asleep and the Rite of Awakening, a ritual dedicated to Anubis to awaken him from his sleep. The dagger can sip the blood it is dipped on, leaving no blood on its blade.

Appearances

 * Season 4
 * Sex and Violence
 * Season 13
 * Good Intentions
 * Supernatural: Children of Anubis