Assertion: mild steel | /r/HasProperty | hardened
Facets:
value: by increasing the carbon content
type: MANNER
Source sentences:
text: As a rule, mild steels are generally not able to be hardened, since they contain so little carbon.
text: Mild steel must be case hardened.
text: However mild steel can be hardened by increasing the carbon content and surface hardness can be increased through carburizing.