snap line vs chalk line

snap line and chalk line both are nouns.

Word	Noun	Adjective	Verb	Adverb
snap line	Yes	No	No	No
chalk line	Yes	No	No	No

As nouns, snap line and chalk line are synonyms defined as:

snap line and chalk line: a chalked string used in the building trades to make a straight line on a vertical surface

Other synonyms of snap line include snapline.

snap line (noun)	chalk line (noun)
a chalked string used in the building trades to make a straight line on a vertical surface	a chalked string used in the building trades to make a straight line on a vertical surface