How to Harden Steel at Home
- 1). Heat the section of mild steel to be hardened evenly with an oxyacetylene torch until it is a bright cherry-red color.
- 2). Immerse the hot steel in a container of case hardening compound. Cover the steel and let it cool down. Due to the insulating properties of coarse powdery case hardening compound, this may take an hour or two.
- 3). Remove the steel from the hardening compound and reheat it to a cherry-red color. Quench the steel immediately by immersing it in a bucket of cold, clean water.
- 4). Clean off the mill-scale with a wire brush and test the hardness of the material by rubbing a file over the surface. Repeat the above hardening sequence to increase both the hardness and depth of the layer of case hardened steel.
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