CIRP Encyclopedia of Production Engineering

2019 Edition
| Editors: Sami Chatti, Luc Laperrière, Gunther Reinhart, Tullio Tolio

Superhard Tools

  • Eckart UhlmannEmail author
  • Fiona Sammler
  • John Barry
  • Javier Fuentes
  • Sebastian Richarz
Reference work entry



Superhard materials for defined edge tooling may be defined as materials with a hardness exceeding 3,000 HV.


Superhard materials also exhibit other properties which are favorable in tooling materials such as high thermal conductivity, low coefficients of thermal expansion, and low coefficient of friction on most materials. All commercial superhard materials fall within the two broad categories of diamond or cubic boron nitride (CBN). Diamond is well known as the hardest material, with single crystal diamond exhibiting hardness values of approximately 10,000 HV. Diamond materials however can be most conveniently categorized according to their microstructure/structure and corresponding method of manufacture. The five categories of “synthetic” diamond materials can thus be identified as:
  • Polycrystalline diamond or “PCD” is produced by sintering micron diamond powders under ultrahigh pressure (>5 GPa) in the presence of a...

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Copyright information

© CIRP 2019

Authors and Affiliations

  • Eckart Uhlmann
    • 1
    Email author
  • Fiona Sammler
    • 3
  • John Barry
    • 2
  • Javier Fuentes
    • 3
  • Sebastian Richarz
    • 3
  1. 1.Fraunhofer Institute for Production Systems and Design TechnologyBerlinGermany
  2. 2.Advanced MaterialsElement Six LtdShannonIreland
  3. 3.BerlinGermany

Section editors and affiliations

  • Garret O'Donnell
    • 1
  1. 1.Trinity College DublinDublinIreland