The Ball End Mill from Ball is a high-speed steel end mill with a ball nose end. It has a 1/4" shank diameter, 1/2" overall length, and a 1/4" cutting diameter. The end mill has 2 flutes and a right hand spiral. It is designed for general purpose milling in materials like aluminum, brass, bronze, and plastics. The ball nose end allows milling of 3D contoured surfaces.