helve vs mandrel

helve

noun
  • The handle or haft of a tool or weapon. 

  • A forge hammer lifted by a cam acting on the helve between the fulcrum and the head. 

verb
  • To furnish (an axe, etc.) with a helve. 

mandrel

noun
  • 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. 

  • 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. 

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