Burnishing is a process by which a smooth hard tool (using sufficient pressure) is rubbed on the metal surface. This process flattens the high spots by causing plastic flow of the metal.The edges of sheet metal can be smoothed out by pushing the sheet metal through a die that will exert a compressive force to smooth out the blanked edge and the burrs caused by the die break.
Roller Burnishing improves the finish and size of surfaces of revolution such as cylinders and conical surfaces. Both internal and external surfaces can be burnished using an appropriate tool.
Burnishing improves the surface finish, surface hardness, wear-resistance, fatigue and corrosion resistance.