gangsaw vs sawing machine

gangsaw and sawing machine both are nouns.

Word	Noun	Adjective	Verb	Adverb
gangsaw	Yes	No	No	No
sawing machine	Yes	No	No	No

As nouns, sawing machine is a hypernym of gangsaw; that is, sawing machine is a word with a broader meaning than gangsaw:

gangsaw: a power saw that has several parallel blades making simultaneous cuts
sawing machine: a power tool for cutting wood

Other hypernyms of gangsaw include power saw, saw.

gangsaw (noun)	sawing machine (noun)
a power saw that has several parallel blades making simultaneous cuts	a power tool for cutting wood