A Brief Introduction to the Application of End Mills
The main cutting edge of the end mill is the cylindrical surface, and the cutting edge on the end surface is the secondary cutting edge. An end mill without a center edge cannot perform a feed motion along the axial direction of the milling cutter.
Standard end mills are available with coarse and fine teeth. The number of teeth of the coarse-tooth end mill is 3 to 4, and the helix angle β is larger; the number of teeth of the fine-tooth end mill is 5 to 8, and the helix angle β is smaller. The material of the cutting part is high-speed steel, and the shank is 45 steel.
The effect of different helix angles of carbide end mills on machining performance?
The larger the helix angle of the end mill, the longer the contact line between the workpiece and the blade, and the smaller the load applied to the blade of unit length, which is beneficial to the life of the tool. On the other hand, as the helix angle increases, the axial component of the cutting resistance also increases, making the tool easy to fall off the tool holder. Therefore, when machining with a tool with a large helix angle, a strong and rigid tool holder is required. A helix angle of 0° is called a straight edge, and its contact line is the shortest.
The thermal conductivity of stainless steel is low, the cutting of difficult-to-cut materials that have a great influence on the tool nose, and the use of end mills with a large helix angle are beneficial to the life of the tool. For high-hardness workpieces, as the hardness increases, the cutting resistance will increase, and the end mill with a large helix angle is beneficial to the tool life. On the other hand, choosing a tool with a large helix angle is likely to increase the cutting resistance. Right For a helical tool, the cutting resistance acting on the tool is downward, which makes the tool easy to fall off. Therefore, it is necessary to adopt a countermeasure with a high rigidity holder. Even if the rigidity of the tool is ensured, the rigidity of the workpiece such as thin plate machining is low. End mills with small helix angles.
The effect of the number of teeth of carbide end mills on machining performance?
The number of flutes is selected by the cutting method of the end mill. For example, for groove cutting with the same cutting width and the same tool diameter, a large-capacity chip flute is required. Usually, a tool with 2 flutes is used. For side cutting with a small cutting width, choose Multi-edge end mills that prioritize tool rigidity.
With the increase in the number of cutting edges, the rigidity and machining efficiency (tool life) can be improved, but at the same time, the discharge of chips will become weaker. However, the appropriate selection of cutting conditions can overcome the weakness of chip discharge, and multi-edge cutting is the direction of future development.