Mass finishing equipment and tumblers use loose abrasives or tumbling media combined with cleaning or polishing compounds to bulk-finish parts. Examples of mass finishing equipment and tumblers include tumblers and rotary barrels, centrifugal drums, centrifugal discs, drag or spindle finishers, and vibratory finishers. A mass finishing machine or mass finisher can be used for finishing, cleaning, coloring, brightening, deburring, burnishing, deflashing, polishing, refinishing or stripping production parts. Mass finishing equipment and tumblers vary in terms of performance specifications such as aggressiveness and finishing speeds.

Selecting mass finishing equipment and tumblers requires an understanding of finishing processes such as burnishing and peening. Burnishing is a finishing process in which a smooth, hard tool is rubbed over a metal surface. By applying a sufficient amount of pressure, a burnishing mass finishing machine can flatten out higher spots by causing the metal to flow. Roller burnishing is used to improve the finish of cylinders and cones. Burnishing can also be used to improve surface finish, hardness, fatigue, and corrosion resistance. Peening is another process which mass finishing equipment and tumblers perform to improve the surface of metal surfaces. During the peening process, pellets or hammers are used to blast the surface of the metal.

Mass finishing equipment and tumblers includes sandblasters, rock tumblers, and deburring equipment. Sandblasters are used to smooth and clean hard surfaces. During sandblasting, solid particles are forced onto a metal surface at high speeds. Rock tumbling is another method for smoothing and polishing metals and hard surfaces. Unlike other mass finishing equipment and tumblers, a rock tumbler consists of a barrel that is loaded with rocks, lubricant and grit. As the barrel rotates, the rocks slide past each other and polish the hard surface. Deburring equipment is used to remove burrs, sharp snags or metal tears, which result from metal stamping processes. Deburring can be performed by tumbling finished parts in a barrel.