Blackening Agents For Metal - Blackening agents for metal are chemicals used to create a black oxide or blackened finish on metal surfaces. This process enhances corrosion resistance, reduces light reflection, and improves aesthetics. Here are some common blackening methods: 1. Cold Blackening (Room Temperature) Chemicals Used: Copper selenide, selenium dioxide Metals: Steel, iron, stainless steel, aluminum, brass Process: Chemical immersion at room temperature Pros: Quick, easy to apply, minimal heating required Cons: Less durable than hot black oxide, requires sealing with oil or wax 2. Hot Black Oxide (High Temperature) Chemicals Used: Sodium hydroxide, nitrates, nitrites Metals: Steel, stainless steel, cast iron Process: Immersion in a heated (285°F / 140°C) alkaline bath Pros: Highly durable, excellent corrosion resistance (when sealed with oil) Cons: Requires strict temperature control and safety precautions. # Blackening Chemical Manufacturer.