metallographic sample vs metallographic specimen

metallographic sample and metallographic specimen both are nouns.

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

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

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

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