The Grainger Approved Square End Mill Single End is a high-speed steel end mill with a square end for milling slots, keyways, and pockets. It has four flutes and a right-hand spiral. The overall length is 3 inches and the shank diameter is 0.25 inches. This end mill is uncoated and made in the USA. It can be used for a variety of materials including low carbon steel, brass, aluminum and plastic. The square end allows milling of corners and edges.