capillary tube vs capillary tubing

capillary tube and capillary tubing both are nouns.

Word	Noun	Adjective	Verb	Adverb
capillary tube	Yes	No	No	No
capillary tubing	Yes	No	No	No

As nouns, capillary tube and capillary tubing are synonyms defined as:

capillary tube and capillary tubing: a tube of small internal diameter; holds liquid by capillary action

Other synonyms of capillary tube include capillary.

capillary tube (noun)	capillary tubing (noun)
a tube of small internal diameter; holds liquid by capillary action	a tube of small internal diameter; holds liquid by capillary action