profit margin vs margin of profit

profit margin and margin of profit both are nouns.

Word	Noun	Adjective	Verb	Adverb
profit margin	Yes	No	No	No
margin of profit	Yes	No	No	No

As nouns, profit margin and margin of profit are synonyms defined as:

profit margin and margin of profit: the ratio gross profits divided by net sales

Other synonyms of profit margin include gross margin.

profit margin (noun)	margin of profit (noun)
the ratio gross profits divided by net sales	the ratio gross profits divided by net sales