These roughing end mills have a sinusoidal chipbreaker form which produces small chips, allowing them to run at faster speed rate than conventional tools, resulting in high material removal rates. Designed to machine difficult and abrasive materials, ranging from medium to highest hardness level machinable by High Speed steel. The 8% Cobalt content assures high edge hardness at elevated temperture levels. The large core diameter provides rigidity and reduces deflection. They can be used for general purpose rough milling including profiling and open ended slots.