These sets contain multiple carbide corner-radius end mills in a range of sizes. Sometimes called bull-nose end mills, corner-radius end mills have a square nose with slightly rounded corners that help distribute cutting forces evenly to prevent damage to the end mill and extend its life. They are rotated against a piece of stock to create a flat-bottomed groove with slightly rounded inside corners in milling applications that require a specific radius. Carbide end mills provide excellent wear resistance, heat resistance, and hardness.