End mill is a metal-cutting tool widely used in mechanical engineering, designed for processing various planes, ledges, grooves and shaped surfaces of complex geometry. The main feature of this tool is the possibility of simultaneous processing of two perpendicular planes, due to the presence of teeth both on the cylindrical and on the end surface of the cutter.
At its core, a face mill is a multi-bladed cylindrical metal-cutting tool, where each tooth is an independent cutter. Thanks to its design and high speeds of the machine, a high degree of cleanliness of the surface processed by milling is achieved. As the tool rotates, its teeth (cutters) alternately come into contact with the material.
The face milling cutter when performing a metal-cutting operation is located perpendicular to the machined planedetails. In this case, the main cutting load is assumed by the cutting side edges located on the outer cylindrical surface, which contributes to their rapid wear. Of course, end mills can be reground, but after such an operation, their dimensions will invariably differ from the nominal ones.
In this regard, prefabricated cutters with interchangeable cutters made of various grades of high-speed steels and equipped with brazed carbide inserts or cutting elements made of cermet are especially popular. Such cutters and plates are fixed directly on the tool body. A distinctive feature of this type of cutter is the fixed installation of the cutting element relative to the tool body. Face mills of this design have a constant geometry, determined by the accuracy of the corresponding base surfaces of the tool body and the configuration of removable non-regrindable inserts.
The main advantages of this design solution include increased strength, due to the absence of internal stress of the metal, usually caused by regrinding. This increases the tool life and durability by about thirty percent. In addition, such cutters equipped with removable inserts can significantly save carbide material, since the used cutters can be sent for remelting, where tungsten and other expensive elements are extracted from them.
For endmilling is characterized by higher productivity than for cylindrical. Nowadays, most of these operations are carried out with end mills. The geometry of the teeth also deserves special attention. The cutting surface of each of them has working edges sharpened at a certain angle, which pass through the top of the tooth. Distinguish between the main and auxiliary cutting surfaces. The top of the teeth of the end mill can have either a rectilinear shape or rounded contours. The latter option demonstrates increased wear resistance and less dependence on the degree of runout of the cutting edge. These cutters are mainly used in roughing and semi-finishing.
For milling operations on the processing of small ledges and even open planes, a shell end mill equipped with insert knives, which are made of various grades of high speed steels, is usually used. Such a model, mounted on the mandrel or seat end of the machine spindle, usually has a diameter of 40 or more millimeters, which makes it a fairly rigid and massive tool.
