Ceramic Media, Tri-Angle, 3/8" x 3/8" - ACT-001 Ceramic Media: General Purpose "M" A high performance media, that has the unique combination of fast burr removal and low media loss. Good for mild steel and some aluminum alloys. Super Fast Cutting "SF" A tough, fast cutting media where the primary concern is fast burr removal, resulting in slower time cycle. Primarily used on steel.