The 3300 General Purpose end mill has 3-flutes and was designed for use in titanium, super alloys, stainless steels, steels, cast iron, brass & copper, high si aluminum, and low si aluminum.3-Flute - 30° Helix - 3300 GP End Mills, TIALN, RH Spiral, Square, Standard, 13/64 The 3300 General Purpose end mill is stocked uncoated and with TiAlN, TiCN, and TiN coatings..