steamfitter vs craftsman

steamfitter and craftsman both are nouns.

Word	Noun	Adjective	Verb	Adverb
steamfitter	Yes	No	No	No
craftsman	Yes	No	No	No

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

steamfitter: a craftsman who installs and maintains equipment for ventilating or heating or refrigerating
craftsman: a skilled worker who practices some trade or handicraft

Other hypernyms of steamfitter include artificer, artisan, journeyman.

steamfitter (noun)	craftsman (noun)
a craftsman who installs and maintains equipment for ventilating or heating or refrigerating	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