hand ax vs hand axe

hand ax and hand axe both are nouns.

Word	Noun	Adjective	Verb	Adverb
hand ax	Yes	No	No	No
hand axe	Yes	No	No	No

As nouns, hand ax and hand axe are synonyms defined as:

hand ax and hand axe: a stone tool with a cutting edge; the stone is held in the hand and used for chopping

hand ax (noun)	hand axe (noun)
a stone tool with a cutting edge; the stone is held in the hand and used for chopping	a stone tool with a cutting edge; the stone is held in the hand and used for chopping