Choosing the right kind of tumbling media for a specific job can be difficult. There are many shapes, sizes, and materials to choose from, and not all of them behave the same. So, knowing what features to look out for can make the process much easier. In general, there are three factors that define the aggressiveness of tumbling media.
First, it’s important to take the shape into account. Typically, the cleaning requirements will dictate the shape of the media. Some shapes are perfect for heavy cleaning while others are great for fine polishing. Cylinder, ball, and pyramid are the most common shapes of tumbling media.
Second, size matters when dealing with tumbling media. In most cases, small media is perfect for cleaning small parts while larger media is better for larger parts. Plus, the smoothness of the finish will depend on the media size.
Finally, the material and its abrasive qualities will define the cleaning process. More aggressive media is great for hard cleaning or deburring. On the other hand, less aggressive media is best for polishing.
In essence, friction is the driving force that cleans and polishes parts. As the media and the parts tumble or vibrate together, the abrasive material will create friction. So, choosing the right media is key to success.
Steel media is the most abrasive of all types of media. In general, it’s perfect for heavy deburring of steel parts. It can also clean other materials, such as plastic, aluminum, or brass. Apart from cleaning, steel media can also be used for polishing and shining.
In the end, the size of the steel media will play the most important role. If the media is small, the cleaning process will take longer. But larger media will deburr metal parts fairly quickly. On top of all that, steel media is durable and long-lasting.
Plastic media is less abrasive than steel media. That’s why it’s mainly used to deburr, polish and burnish metal parts.
In most cases, plastic media will work best on softer metals like brass and aluminum. Since plastic is also a soft material, it will cause less damage to delicate surfaces. The end result will be a smooth matt finish.
As for the shapes, plastic media most often comes in a pyramid or cone shape.
Ceramic media can be used for light or heavy deburring. It’s abrasive enough for paint or rust removal. On top of that, ceramic media is great for polishing stainless steel and aluminum.
In addition, the shape will impact the cleaning job the most. For example, cylindrical media is perfect for treating tough metals, like steel. On the other hand, spheres are better suited for polishing softer metals, like aluminum or brass.
Two types of organic media are the most common — corn cob and walnut shell. They are the least abrasive type of media. So, it’s best to use them for cleaning and polishing delicate surfaces like jewelry or wristwatches.
In most cases, organic media will last for up to 20 runs. In other words, it won’t retain its abrasive qualities for a long time.