• Webster's Revised Unabridged Dictionary
    • n Casehardening The act or process of converting the surface of iron into steel.Casehardening is now commonly effected by cementation with charcoal or other carbonizing material, the depth and degree of hardening (carbonization) depending on the time during which the iron is exposed to the heat. See Cementation.
    • ***
Century Dictionary and Cyclopedia
    • n casehardening In metallurgy, a rapid process of cementation, in which the surface of wrought-iron is converted into steel by heating the article to be treated in an iron box, in contact with some animal matter, such as bone, parings of horses' hoofs, or leather. This is done in a smith's forge, or in any suitable furnace.
    • n casehardening A process of induration affecting surfaces of rocks. It accompanies evaporation of moisture from the capillary system of exposed surfaces, and consequent deposition of such mineral matter as is held in solution. The result is a hard film or layer produced by extra cementation. In arid regions such hardened films, polished by blown sand, are known as desert varnish. Van Hise, U. S. Geol. Surv., Monograph 47, p. 547.
    • ***


In literature:

The same salt may be used to caseharden wrought iron.
"Scientific American Supplement, No. 430, March 29, 1884" by Various
Many of the parts are of cast iron, rendered malleable by annealing, and finally casehardened.
"Scientific American Supplement, No. 598, June 18, 1887" by Various
Pack the pieces to be casehardened in the iron box so as not to touch each other or the box.
"Burroughs' Encyclopaedia of Astounding Facts and Useful Information, 1889" by Barkham Burroughs
But I must take exercise, and caseharden myself.
"The Journal of Sir Walter Scott" by Walter Scott
A casehardened lawyer like myself would do that.
"Lippincott's Magazine, November 1885" by Various
Nowhere else have I seen rocks casehardened with primal mud.
"Under the Maples" by John Burroughs
I have a peculiar kind of steel which I cannot harden by fire and water, neither will it caseharden by prussiate of potash.
"Scientific American, Vol. XXXIX.--No. 24. [New Series.], December 14, 1878" by Various