HOT BLACKENING SALT (VCFRROUS)
The hot blackening salt process involves immersing the metal parts in a hot bath of specific salts and chemicals. The bath typically contains a mixture of sodium hydroxide (caustic soda), nitrates, and other proprietary chemicals. The metal parts are heated to a high temperature (usually around 285-290°C or 545-555°F) and immersed in the hot salt solution for a certain period, typically ranging from several minutes to half an hour, depending on the desired thickness of the black oxide coating.
