People call processing hardness exceeds 56hrc, or intensity than rm> 2000n / mm2 of steel materials for hard machining. In most cases, molding or die after the pre-processing, or to go through carburizing quenching. After the pre-processing, you must reserve a certain finishing allowance. Especially when machining a workpiece with a spherical or toroidal shape, the hard milling is more important. Hard milling can be cut to 70hrc material hardness, surface roughness is generally required only by means of a hand-polished to achieve, which is a very expensive process step. In order to shorten the time required for manual polishing, must use to determine the geometry of the blade has when milling. As hsc processing, close to the surface roughness of the polished surface: the maximum surface quality rz1. Common on the market are not suitable for hard metal cutters cutting in this range. Solve the problem of hard milling materials, some prerequisites must be met. For example, by using special cemented carbide substrate material, having a unique geometry and the corresponding coating milling. This means that the tool must have these three important elements. In the manufacturing process of the tool, you must pay special attention to the balance between these elements.