Birchwood Technologies, Black Oxide, Mid-Temperature Black Oxide, Room-Temperature Black Oxide, Antiquing and Oxidizing, Aluminum Oxide, Zinc Phosphate, Rust Preventatives, Metal Finishing Systems; TRU TEMP 190 Degrees Black Oxide Process For In-House Blackening of Iron & Steel. Durable Satin Magnetite Finish.000020 Inch Thick. NO EPA REGULATED METALS ...