Sand or bead-blasting is a process of altering the finish of a metal surface by subjecting the surface to a stream of glass bead, sand or aluminium oxide particles delivered via high pressure. The surface becomes matt and the majority of any remaining small burrs can be removed. It can be both used for functional as well as aesthetic reasons.

Tribofinition

The chemical mechanical polishing, tumbling , vibratory finishing or trovalisation is a method for modifying the surface state and the metal parts of edges, plastic, ceramic, etc. by immersing in an abrasive mixture moved vibratory, oscillatory, or rotating in an open or closed vessel.

The result obtained (eg cleaning, stripping, de-burring, shelving, polishing, matte effect) is due to friction between the parts and the abrasive mixture, and depends on the type of equipment used, the composition of the abrasive mixture, speed settings and the duration of the operation. -Wikipedia-

The below system used in the manufacture of balances and escapements uses irregular shaped copper pieces mixed with silver oxide polishing powder in water, then placed in a special machine which causes the vessel to vibrate with the components moving freely inside the jar with the mix.

The ceramic material below is used in the same way as the above copper pieces but with out polishing powder, immersed in water.

The same process is shown below and is illustrated above but using steel pins in different sizes.