Sting (Middle-earth)
Sting has the magical ability to detect orcs or goblins nearby, glowing blue in their presence, as it did when the Fellowship encountered orcs in the mines of Moria. Tolkien establishes this as a common property of First Age Elf blades, particularly those forged in Gondolin. Sting is also exceptionally sharp. Bilbo manages to thrust it without effort deep into a wooden beam at Rivendell. Frodo also wounds a troll in Moria, after Boromir notches his own sword with his attempt. Sam uses Sting to cut through the giant spider Shelob's strong webs with ease, and also wound the spider, driving it away from the paralyzed Frodo.
The Hobbit
Another influence from Old English sources is the appearance of named blades of renown, adorned in runes. In using his elf-blade Bilbo finally takes his first independent heroic action. By his naming the blade "Sting" we see Bilbo's acceptance of the kinds of cultural and linguistic practices found in "Beowulf", signifying his entrance into the ancient world in which he found himself. This progression culminates in Bilbo stealing a cup from the dragon's hoard, rousing him to wrath—an incident directly mirroring "Beowulf" and an action entirely determined by traditional narrative patterns. As Tolkien wrote, "The episode of the theft arose naturally (and almost inevitably) from the circumstances. It is difficult to think of any other way of conducting the story at this point. I fancy the author of Beowulf would say much the same."