drafting vs mechanical drawing

drafting

noun
  • A method of preparing fibers for weaving. 

  • The act or process of producing a technical drawing, or draft. 

  • The practice among ground vehicle drivers or cyclists of following in a close line to reduce wind resistance. 

  • A profession, usually related to making technical drawings for architecture, engineering, or manufacturing. 

mechanical drawing

How often have the words drafting and mechanical drawing occurred in a corpus of books? (source: Google Ngram Viewer )