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. The mill diameter is 0.375 inches with a 0.125 inch shank length. It has an American National Standard Stub length shank and is made in the USA. The end mill's composition is M2 high speed steel which provides good wear resistance and allows higher cutting speeds than regular carbon steel end mills. It can machine steels, cast iron, aluminum, copper, brass and plastics.