A practical guide covering ceramic, plastic, and steel media — when to use each based on material hardness, component geometry, and desired surface finish.
Why media selection matters
The finishing media is the single most important variable in your vibratory process. Choose the wrong type and you'll either damage your components, achieve a poor finish, or find the process takes far longer than it should. Choose correctly and you'll get consistent, fast results with minimal media consumption.
The main media types
Ceramic media
Ceramic media is the most widely used type. Made from aluminium oxide or silicon carbide bonded in a ceramic matrix, it offers a high cut rate and is suitable for ferrous and non-ferrous metals. Ceramic media comes in a wide range of shapes — cones, cylinders, triangles, wedges, and stars — each suited to different component geometries.
- Best for: Steel, stainless steel, cast iron, aluminium (harder alloys)
- Typical uses: Deburring, descaling, edge radiusing
- Cut rate: High to medium depending on grade
Plastic media
Plastic media is made from a polyester resin matrix with abrasive particles. It is lighter and less aggressive than ceramic, making it ideal for softer metals and components requiring a finer finish. It also tends to leave a brighter surface.
- Best for: Aluminium (softer alloys), brass, copper, zinc, soft steels
- Typical uses: Light deburring, burnishing, pre-plate finishing
- Cut rate: Low to medium
Steel media
Steel media — typically stainless steel balls, pins, or ballcones — does not cut the component surface but instead burnishes it, compacting and smoothing the surface layer. The result is a bright, mirror-like finish.
- Best for: Components requiring a high shine with no material removal
- Typical uses: Burnishing, stress relieving, cosmetic finishing
- Cut rate: None (surface compression only)
Tip: When finishing aluminium, always use plastic or ceramic media specifically rated for non-ferrous use. Contamination from ferrous media can cause staining that is difficult to remove.
Choosing media shape
Media shape is critical for components with complex geometry. As a general rule:
- Cones and wedges — access holes, slots, and recesses
- Cylinders — general purpose, flat surfaces
- Triangles and stars — reach into corners and internal features
- Balls — burnishing, simple geometries
Media size
Media should always be larger than the smallest hole or recess on the component — otherwise media will become lodged and is very difficult to remove. As a rule of thumb, use media that is at least 1.5x the size of the smallest feature on the part.
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