pipe fitter vs craftsman

pipe fitter and craftsman both are nouns.

Word	Noun	Adjective	Verb	Adverb
pipe fitter	Yes	No	No	No
craftsman	Yes	No	No	No

As nouns, craftsman is a hypernym of pipe fitter; that is, craftsman is a word with a broader meaning than pipe fitter:

pipe fitter: a craftsman who installs and repairs pipes and fixtures and appliances
craftsman: a skilled worker who practices some trade or handicraft

Other hypernyms of pipe fitter include artificer, artisan, journeyman.

pipe fitter (noun)	craftsman (noun)
a craftsman who installs and repairs pipes and fixtures and appliances	a skilled worker who practices some trade or handicraft
	a creator of great skill in the manual arts
	a professional whose work is consistently of high quality