As we all know, there are so many types of media in the world. For example, the stainless steel must be spark-resistant, non-magnetic steel in the 300-series. Alloys 304 and 316 are the most common stainless steels of this type. However, in Ball millhigh-density alumina ceramic media is the type I’ve heard of most often being used. Nowadays, people are paying more attentions to keep healthy. Here, I must emphasize there is an ongoing discussion and debate about what is the “safest” media to use when milling.

Each type of media has its advantages and disadvantages. It is when one gets into milling mixed compositions like black powder that the dangers arise. We simply don’t want sparks generated in the mill jar during that process for obvious reasons. Ceramic is hard, does not wear out quickly, but some types of ceramic do spark. Some people have said that if they bang pieces of their ceramic media together in the dark, they can see little sparks being generated. Others say that these are just little luminous ‘light’ sparks and they don’t present a danger in milling.

Lead or brass is reliably the only really spark-free media and is considered to be the standard for milling comps like BP. But lead is softer than the other media and will wear down over time. If one mills a white powder like potassium nitrate with lead media, the powder will come out of the mill gray. That presents a danger of lead poisoning if one breathes a lot of that smoke. And also, there are many reports about lead poisoning recently, which is taken seriously all over the world. But lead media has probably been and will continue to be used more than any other in amateur pyrotechnic milling.

As a word, nothing is perfect. Any thing is a double-edged sword, and has its benefits and risks. We shall take good use of its advantages and keep watch for its risks to the best.