hobnail vs studs

hobnail

noun
  • A short nail with a thick head, typically used in boot soles. 

verb
  • To tread down roughly, as with hobnailed shoes. 

  • To fit with hobnails. 

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 hobnail and studs occurred in a corpus of books? (source: Google Ngram Viewer )