metallographic specimen vs metallographic sample

metallographic specimen and metallographic sample both are nouns.

Word	Noun	Adjective	Verb	Adverb
metallographic specimen	Yes	No	No	No
metallographic sample	Yes	No	No	No

As nouns, metallographic specimen and metallographic sample are synonyms defined as:

metallographic specimen and metallographic sample: a sample of metal, carefully prepared for analysis.

metallographic specimen (noun)	metallographic sample (noun)
a sample of metal, carefully prepared for analysis.	a sample of metal, carefully prepared for analysis.