Is there a particular reason why Norse mythology depicts Thor wielding a hammer when warhammers were not a common Viking weapon?

by ATiredSaltMiner

In the Norse mythology, Thor is depicted wielding his faithful magic hammer, Mjolnir. However, as far as I know, Viking armaments typically consisted of spears, saex, axes, and swords for the more wealthy. Was using a hammer as a weapon based on some Old Germanic customs, or was it just a literary device in the sagas?

Jonnyfivedicks