One flute square end mills for cutting soft metals such as aluminum are a high performance mill. CNC milling of aluminum can be difficult, the material can stick to the flutes and the chips can "gum" the flutes. These mills are designed for optimal swarf removal and are forgiving when using smaller format CNC machines for both slot and pocketing. For a cleaner side finish when pocketing, other options include 2 and 3 flute cutters for soft metal. Soft / non ferrous metals include aluminium, brass and copper.