old-timer vs old hand

old-timer and old hand both are nouns.

Word	Noun	Adjective	Verb	Adverb
old-timer	Yes	No	No	No
old hand	Yes	No	No	No

As nouns, old-timer and old hand are synonyms defined as:

old-timer and old hand: an experienced person who has been through many battles; someone who has given long service

Other synonyms of old-timer include old stager, oldtimer, stager, veteran, warhorse.

old-timer (noun)	old hand (noun)
an elderly man	an experienced person who has been through many battles; someone who has given long service
an experienced person who has been through many battles; someone who has given long service