For roughing hardened materials, four-flute end mills or higher are recommended. This will provide small chip loads while having the ability to cut at higher feed rates. Additionally, torus end mills are recommended for roughing because the sharp edges of conventional end mills are not sufficiently resistant to the possibilities of vibration and thermal stress when cutting hardened materials.

The selection of cutting tools should be short with short flute lengths along with a helix angle of approximately thirty degrees. A thirty-degree helix has proven to be optimal for chip flow and dispersal of heat. The parent carbide substrate should also be considered. Only fine or ultrafine-grain sintered carbides should be used. Sintered hard carbide is a composite material based on powder metallurgy. A binder (usual cobalt) is used to bond carbide particles. Tungsten-, titanium-, tantal- or niobcarbide are the most used elements and provide the required hardness at high temperatures and wear resistance. With a reduction of the grain size of the carbide particles to about 0.5 to 0.6fm, the edge strength can be further increased, while the tendency to adhesion can be reduced. For larger hardened cavities and cores, a selection of inserted cutting tools should be considered. Carbide inserts are less expensive than end mills and by rotating the insert, insert life can be extended. However, these tools are not typically designed for high spindle speeds and runout can be significant. There is also a significant safety risk if improper handling occurs.

Hard milling creates a great amount of stress on the tool from high heat and abrasive wear. To help overcome these stresses, coatings must be applied to the cutting tool. These coatings offer a protective layer on the tool, substantially increasing its life. The most common coatings are titanium nitride (TiN), titanium carbon nitride (TiCN), titanium aluminum nitride (TiAlN) and titanium aluminum carbon nitride (TiAlCN)