VCFEROUS HOT BLACKNING CHEMICLE Hot Blackening: a. Prepare the blackening solution according to the manufacturer's instructions. The blackening chemical usually contains a mixture of sodium hydroxide, sodium nitrite, and other proprietary additives. b. Heat the blackening solution to the recommended temperature, typically between 285°C to 315°C (545°F to 600°F) for the blackening process to occur effectively. c. Immerse the mild steel parts into the hot blackening solution for the specified duration. The immersion time will depend on the specific blackening chemical being used, but it usually ranges from a few minutes to half an hour. d. Monitor the blackening process carefully to achieve the desired black oxide coating. The immersion time may vary depending on the desired thickness of the black oxide layer.