Sigurd's mythic sword reforged by Reginn, capable of splitting an anvil.

Gramr was Sigurd's legendary sword, originally a weapon that Óðinn thrust into the tree trunk Barnstokkr in the hall of the Völsungs. Sigmundr drew it out and bore it until his death, after which the fragments were reforged by Reginn into the perfect sword Gramr.

With Gramr Sigurd slew the dragon Fafnir and laid the sword naked in the earth as a chastity boundary between himself and Brynhildr during the night he kept vigil over her. It is a central symbol of lineage, fate, and heroism in Völsunga saga.

Attestations

Völsunga saga 13
Describes Reginn's reforging of Gramr and the test against the anvil.