hard as iron vs uphill

hard as iron

adj

  • very hard 

uphill

adj

  • Difficult or laborious. 

  • Located up a slope or on a hill. 

  • Going up a slope or a hill. 

noun

  • An uphill route. 

adv

  • Up a slope, towards higher ground. 

  • With difficulty. 

How often have the words hard as iron and uphill occurred in a corpus of books? (source: Google Ngram Viewer )