Thermal spraying is an industrial coating process in which fine particles of molten or semi-molten metal coating are sprayed at high velocity onto a substrate. In most cases, the substrate is metal, but in some specific cases, the substrate can be plastic.

The thermal spray coating material is typically a powdered metal compound or a wire fed through a feeder. This source material is melted by the high heat generated by a flame or electric arc. Thermal spray coatings enhance the coated surface and protect it from abrasion, erosion, wear, temperature extremes, and corrosion. These coatings can also be used to build undersized components to a desired size.