mandrel vs perforator

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. 

perforator

noun
  • A tool or machine that makes holes, or perforates, materials such as paper and card. 

  • A perforating artery or vein 

  • A machine that can bore a tunnel underground 

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