Invented more than a century ago (and since perfected), burnishing has stood the test of time through its efficiency, versatility and simplicity.
Burnishing is a chipless machining method which cold works the metal without cutting or abrading the surface.
It removes no metal but rather compresses, or “irons-out” the peaks of a metal surface into the valleys, generating a dense and uniform surface.
Roller burnishing improves surface finish and results in dimensional accuracy.
The cold working condenses the grain structure of metal, producing an increase in surface hardness from 50% to 100%, within a penetration of .010” to .030” on the part’s surface.
In roller burnishing, the material is elastically deformed to a given depth below the surface. The result is compressive stresses at the surface. In turn, this increases the resistance of the material to fatigue failure because any external forces must first overcome these residual stresses.