Plating copper often involves very thin coatings and the metal surface needs to be prepared properly to accept the plating. This requires a smooth surface finish and slightly rounded edges the coating can tend to fail on sharp corners and edges.
Getting the proper finish can be done using either wet or dry tumbling. In this case, these parts have very small holes where smaller media can get stuck so dry tumbling was not a consideration.
A wet tumbling process using a general purpose Plastic Triangle Media produced a smooth, matte surface finish and a nicely rounded edge on the external as well as the internal holes of the part. The cycle time for this part was about 4 hours in order achieve the desired rounding and deburring on the finer features of the part.