axletree vs mandrel

axletree

noun
  • A spindle or axle of a wheel. 

  • A stimulus or driving force. 

  • A bar or beam of wood or iron, connecting the opposite wheels of a carriage, on the ends of which the wheels revolve. 

mandrel

noun
  • A round object used as an aid for shaping a material, e.g. shaping or enlarging a ring, or bending or enlarging a pipe without creasing or kinking it. 

  • A tool or component of a tool that guides, grips or clamps something, such as a workpiece to be machined, a machining tool or a part while it is moved. 

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