KnKut Step Drills are made from special moly alloy steel and gold surface treated for maximum lubricity. Dual flute construction drills clean accurate holes in thin materials. Use for all thin metals, rigid plastics such as Plexiglas and wood or composite materials with a thickness equal to or less than the step thickness. When drilling steel with 1/8" or greater thickness, a starter hole of the smallest step diameter will speed the drilling process.