Choosing the proper tumbling media is critical when the geometry or configuration of a part provides a specific challenge. Elements like holes, grooves and slots often can only be deburred with a unique media shape and size.
The slot in this stainless steel part is only 0.050″ wide. Choosing a media that is too large may not ‘attack’ the burr at all but simply roll it inside. A media that is very small (like an abrasive grit) may get into the slotted area but not with enough mass to deburr the edge or could get stuck inside the part.
The long, thin shape of this slot can be deburred using a media with a angled edge. A ceramic angle cut cylinder (ideally 45 degree) with a diameter less than 1/4″ will deburr the inside edge of the slot without getting stuck in the part. Alternatively, a small precision media such as a 4 mm (0.15″) abrasive triangle will be able to fit inside the slot.
The part geometry and the tumbling demands (deburring, polishing, etc.) will determine the media that will best provide the desired results. Take a close look at your parts as there may be alternatives that will provide better, faster and even more cost effective results.