rail spike vs studs

rail spike

noun
  • A type of large nail with an offset head used to fasten a rail or base plate to a wooden railroad tie/sleeper. 

studs

noun
  • A pair of shoes or boots which have studs on the bottom to aid grip. 

  • Tires with metal protrusions used for improved traction on snow and ice in winter. 

How often have the words rail spike and studs occurred in a corpus of books? (source: Google Ngram Viewer )