What Is Ball Burnishing?

A bright, highly reflective surface can be achieved in a vibratory process commonly referred to as ball burnishing.   This specialized process combines the weight and brightness of steel media with compounds designed to produce a specific color and luster in the work piece(s).   It’s major function is to make parts look bright or “burnished”.
In ball burnishing heavy, dense steel media impacts the work piece(s) peening over the peaks
of the surface profile creating a larger area in one plane to reflect light.  This is
perceived visually as shine.   There is no abrasive in the steel media so rough edges, surfaces and burrs are simply rolled or pounded over.  An added benefit to ball burnishing is that the weight of the media and process actually work hardens the surface thereby strengthening the part.
Achieving a high degree of reflectivity, brightness, depth and clarity of finish is sometimes referred to as producing a “mirror” finish.  The quality of an image reflected in the surface of a ball burnished part doesn’t match the sharpness and color of an image reflected by an actual mirror but it does produce a highly reflective part.
So while vibratory finishing doesn’t produce a surface that reflects a distortion free image it can produce bright, shiny, attractive parts with a surface that feels very smooth to the touch.