(as) bold as brass vs crude

(as) bold as brass

crude

noun
  • Any substance in its natural state. 

  • Crude oil. 

adj
  • In a natural, untreated state. 

  • Characterized by simplicity, especially something not carefully or expertly made. 

  • Lacking tact or taste. 

  • Lacking concealing elements. 

  • Pertaining to the uninflected stem of a word. 

How often have the words (as) bold as brass and crude occurred in a corpus of books? (source: Google Ngram Viewer )