Color Case Hardening is a process that carries a lot of mystique with it. In the early days of gunsmithing, before material properties were well understood and high carbon steels created, gun makers had to have ways to increase the pressure and wear capabilities of low carbon steel. To this end, gun parts were packed tightly in crucibles of high-carbon materials such as charcoal, bone, leather, and hoof material. Heating this to a high temperature created a carbon-rich environment which would deposit carbon into the steel. Quenching the metal after a period of heating would trap carbon in the surface of the material and harden it, creating a hardened “case” around the metal to create wear resistance while leaving the core of the metal softer to prevent brittleness and breakage.