What to know before you buy
Grinding steel balls are the densest common milling media, so they put a lot of energy into each impact. This collection covers stainless steel milling media in three grades, sold loose or as matched sets for MSE PRO jars.
Choose the grade first. 304 stainless is the general-purpose option. 316 stainless adds molybdenum for better corrosion resistance, which helps with wet milling and mildly corrosive slurries. 440C is a hardened martensitic stainless steel with higher wear resistance, so it suits hard materials and long runs. Loose media includes the MSE PRO 304 stainless steel grinding balls, 316 grinding balls and 440C balls, each in 1 kg packs.
Media sets take the guesswork out of loading a jar. Each set matches a jar size and grade, from 50 ml to 5 L for planetary mill jars and 500 ml to 5 L for roller mill jars, such as the media set for 100 ml 304SS planetary mill jars. Match the media grade to the jar to limit cross contamination. Our article on factors for choosing milling media has more detail.
Frequently Asked Questions
Which stainless steel grade should I choose for milling?
304 suits general dry milling. 316 resists corrosion better, so choose it for wet milling or slurries. 440C stainless steel balls are hardened for wear resistance, so they suit hard powders and long runs. Match the ball grade to your jar grade.
Should I buy a media set or loose grinding balls?
A media set is sized to fill a specific jar with a suitable mix of ball sizes, so it is the quick way to start. For example, the media set for 1L 304SS roller mill jars matches that jar. Buy loose balls when you need to refill or tune the ball size mix.
Will stainless steel media contaminate my powder?
Some wear is unavoidable, so steel media can add iron, chromium and nickel to the powder. This is fine for many metal and alloy powders, and the high density speeds up milling. For ceramics, battery cathodes or other materials sensitive to metal contamination, consider zirconia or agate media instead.
How much media should I put in a jar?
A common starting point is filling about a third of the jar with balls, then adding powder to fill gaps between them, leaving free space for the balls to move. Ratios vary by mill and material. Matched sets, such as the media set for 250 ml 316SS planetary jars, give a tested loading.
Can I order stainless steel media in bulk or a custom size mix?
Yes. For larger amounts of a listed grade, use the bulk order request form. For a different ball size or a custom set for your jar, send the jar size, grade and target mix through the quote request form.
