Quick answer
Pick abrasive media by substrate, required surface profile and whether media is reclaimable: steel grit for aggressive steel profiling, steel shot for peening/smoother finishes, garnet or oxide for versatile cleaning, and beads or organics for gentler work.
Match media to the job
Angular media (steel grit, garnet, aluminum oxide) cuts fast and builds an anchor profile for coatings. Spherical media (steel shot, glass bead) cleans or peens with a smoother finish.
Soft or organic media (plastic, walnut) strip coatings or clean delicate parts with less base-metal removal.
Reclaim vs expendable
Metallic grit and shot are typically reclaimed in cabinets, rooms and turbine machines — lower media cost at volume. Mineral slag and some sands are often expendable for open blasting.
Always confirm local rules on crystalline silica. Many shops prefer garnet or slag alternatives where silica sand is restricted.
Size and hardness
Finer mesh gives smoother finishes; coarser grades cut faster and leave a deeper profile. Harder media lasts longer on reclaim systems but must suit the substrate — stainless work often needs stainless shot to avoid ferrous contamination.