Iron, steel and casting surfaces are used for coating with oxide layer. Bath installation is done with 70-90% by weight. The product is in powder form, the blacking salt is added slowly to warm water. Bathroom operating temperature is between 135 – 145 0C. When the temperature drops below 1350C, blacking salt is added. After iron, steel and casting surfaces are blackened with blacking salt, they are taken to oil baths, after the lubrication, the parts will look bright and resistant to corrosion.Black phosphate coating products, machine gears, armings such as steel and casting surfaces are made to cover the black color at high temperatures. Following this process, the parts are quickly added to the oil baths, so that the steel surfaces provide maximum corrosion resistance.