As usual, the end mill is initially performed with several cutting blades, or, as they say, with teeth. Among all types of this plumbing device, there is an impressive variety, depending on the geometric design: cylindrical, conical, end, end, worm and others. They are able to process various materials - stainless and hardened steel , wood, graphite, cast iron, copper, aluminum. The material composition of the cutting part of the cutter is always very solid; it can be ceramics, high-speed steel, cermets, diamond stones, an array of carded wire. The design of the cutter is carried out in the whole version, when it completely consists of one material, in the welded version, where the shank and the cutting part are connected by welding. Soldered tools place soldered cutting elements on themselves, and prefabricated ones consist of various materials, however, they are assembled using fasteners - screw, bolt, nut.
The end mill belongs to the group of tools that differ in a special manner of fastening in the collet of the machine. Reliable clamping is performed using a tail of a cylindrical or conical shape. The teeth on the cylindrical section are located exactly like the blades on the tools of the cylindrical type.
The end type is often used together with a manual machine or milling cutter. Wood end mills are divided into:
- end keys with tails of cylindrical and conical shape;
- ordinary with a pitch of teeth of an uneven order;
- hard alloy keys;
- equipped with hard crowns and screw plates;
- for segment keys ;
- for T-grooves.
Manufacturers of mills put on sale a great many varieties of end tools. However, all models share a number of common elements.
- Cutting edges. A typical end mill can accommodate one or more cutting edges. One edge is in demand in cases where high productivity is needed, and the cleanliness of the working surface is a secondary issue. For wood processing, cutters with two cutting edges are used. This provides a balance between the quality of work performed and efficiency. Cutting edges can be made of both high-speed steel and carbide. Carbide tipped router bits tend to cost a bit more.
- Shank. It is characterized by diameter and length. The diameter, as usual, should correspond to what is in the collet of the machine. Collets with dimensions of 8 and 12 mm are considered the standard in European countries. Although most global manufacturers offer additional collets of different diameters to their machines. The length of the shank is not critical.
And finally, a thrust bearing. Not every end mill is equipped with it. The presence of the bearing allows profile milling, without resorting to a parallel stop - the side face of the workpiece takes on this role. Moving rectilinearly along the face, the bearing determines the path of the cutter.