Unferth gave Hrunting to Beowulf as an infallible legendary sword that survived many battles. But when Beowulf fought Grendel’s mother, his sword could not penetrate her armored skin. It even did not scratch her. For this reason, Beowulf had to put aside this weapon and use the giant sword from the monster’s lair. During his battle with the dragon, another sword failed him.
Hrunting was forged by men, while the sword from the cavern was forged by giants. The giants were Cain’s descendants, just as Grendel and his mother. Probably that is why it could kill the monsters. However, the magical sword melted away to the hilt once Beowulf cut off Grendel’s head. The blood of his mother contained poison and was extremely hot for the blade. It was the second time when his sword failed. “It was a wonderful thing, the way it all melted as ice melts.” The narrator associates this transformation with God’s will. However, the giant sword is unnecessary anymore.
The third failing sword in battle was Naegling. The case was like the previous one. Beowulf hit the dragon with his weapon, but it broke against the serpent’s head. As the narrator describes it, “Beowulf’s ancient iron-grey sword let him down in the fight. It was never his fortune to be helped in combat by the cutting edge of weapons made of iron.” This quote highlights Beowulf’s lack of luck in using swords. Due to this accident, the dragon bit Beowulf on his neck. The wound led to the hero’s death.