box end wrench vs spanner

box end wrench and spanner both are nouns.

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

As nouns, spanner is a hypernym of box end wrench; that is, spanner is a word with a broader meaning than box end wrench:

box end wrench: a wrench with a closed loop (a socket) that fits over a nut or bolt head
spanner: a hand tool that is used to hold or twist a nut or bolt

Other hypernyms of box end wrench include wrench.

box end wrench (noun)	spanner (noun)
a wrench with a closed loop (a socket) that fits over a nut or bolt head	a hand tool that is used to hold or twist a nut or bolt