Aluminum is a relatively soft metal and care needs to be taken when tumbling to ensure that the finish is uniform. It is easy to ‘over work’ some areas of a part if the proper media shape, size and type if used. Often light cutting media such as the Plastic or Synthetic Media is used to build a margin of error and prevent too much edge rounding or a rough surface finish.
Sometimes, parts need to have a heavily rounded edge. Ceramic Media is much denser and more aggressive media than Plastic or Synthetic and is used on aluminum in these scenarios. The picture above shows the raw, cut aluminum part (left in picture) with the rough edges and the smooth surface finish.
After vibratory tumbling with an aggressive Ceramic Media, the edges are rounded and the part has a matte, tumbled surface finish. This result was accomplished in less than 1 hour. These results can be achieved with steel parts but the cycle times are typically longer.