Hardening means making a material, particularly a metal, physically harder, and includes particular cases such as:

  • Hardening (metallurgy), the strengthening of metal alloys by heat treatment
  • Case hardening, the process of hardening the surface of a metal by infusing elements into the material's surface forming a thin layer of a harder alloy
    • Case hardening of rocks
    • Case hardening (woodworking)
  • Air-hardening steel
  • Cryogenic hardening
  • Differential hardening
  • Diffusion hardening
  • Fire hardening
  • Hardening of the arteries
  • Induction hardening
  • Laser hardening
  • Precipitation hardening
  • Quenching#Quench hardening
  • a synonym for sclerotization occurring in arthropods
  • Shock hardening
  • Work hardening, also called strain hardening or cold working
    • Strain hardening exponent, a materials constant used in calculations regarding work hardening

It also has the metaphorical meaning of making something more resistant to some threat:

  • Hardening (botany) or cold hardening, the process by which a plant survives freezing temperatures
  • Hardening (computing), the process of securing a system
  • Intellectual property hardening
  • Target hardening, making a military or civilian installation resistant to armed attack
  • Radiation hardening, making a component or installation resistant to ionizing radiation
  • g-hardening, protection of something against high g-force due to acceleration
  • Windows Service Hardening, protection of Microsoft Windows services

It may also mean:

  • Absorption hardening, in nuclear engineering, an increase in the average energy of neutrons by absorption of those of lower energy

Famous quotes containing the word hardening:

    With sixty staring me in the face, I have developed inflammation of the sentence structure and definite hardening of the paragraphs.
    James Thurber (1894–1961)