I'm not sure I'm in the right place for this, if not, Apologies.
In my education material under Construction Steel, in its application it lists Masking Details.
Under Tool Steel it list an application as Maskin Parts.
But nowhere I look or ask have I been able to find an answer as to the difference in meaning between Part and Detail has here. And from my other education material the word 'detail' is used for (as far as I can confirm) anything on a schematic and I've never encountered the word 'part' in such connotation. On the other hand in the workshop I hear the word 'detail' used to refer to anything made.
Oh, and the language I'm taking the education in is Swedish, so I've translated the terms.