This one comes to us from THE MIGHTY THOR vol. 1, issue # 339. Odin invites Thor, Lady Sif and Beta Ray Bill into The furnaces of Nedavellir, the great forges of the Dwarves where Eitri the master Weapon-smith of Asgard casts a second hammer out of molten Uru metal.
Odin then pours a portion of the his life force into the molten hammer and casts an enchantment giving the bearer of this new weapon, Stormbreaker, all of the powers and abilities of Thor.
Eitri instructs Bill (Thor's new ally and equal in both strength and virtue who Odin has appointed as protector of Asgard and the realm eternal,) to pull the molten Stormbreaker out of the forge so that the enchantment can hold.
What comes next is one of my favorite comic book pages of all time:
-"By Ymir's frosty beard!"