box end wrench vs box wrench

box end wrench and box wrench both are nouns.

Word	Noun	Adjective	Verb	Adverb
box end wrench	Yes	No	No	No
box wrench	Yes	No	No	No

As nouns, box end wrench and box wrench are synonyms defined as:

box end wrench and box wrench: a wrench with a closed loop (a socket) that fits over a nut or bolt head

box end wrench (noun)	box wrench (noun)
a wrench with a closed loop (a socket) that fits over a nut or bolt head	a wrench with a closed loop (a socket) that fits over a nut or bolt head