Selection of specifications for end mills in large-scale mold processing

In large-scale mold processing, the selection of end mill specifications needs to comprehensively consider factors such as tool diameter, edge length, number of edges, material, coating and neck shape. The following is a specific analysis:

Tool diameter: The selection of the diameter of the end mill cutter should mainly take into account the requirements of the workpiece’s processing dimensions and ensure that the power required by the tool is within the rated power range of the machine tool. Large-diameter end mills are suitable for large-area cutting, such as mold manufacturing. Generally speaking, the larger the diameter, the better the rigidity of the cutting tool. However, it is also necessary to consider whether the power of the machine tool and the spindle speed can meet the cutting requirements. For instance, when processing large-area mold cavities, end mills with larger diameters can be selected to enhance processing efficiency.

Edge length: The edge length is related to the depth and accuracy of the processing. In large-scale mold processing, if deep cavities or holes need to be processed, end mills with sufficient cutting edge lengths should be selected. However, if the cutting edge is too long, it will affect the rigidity of the tool, causing vibration during cutting and affecting the machining accuracy and surface quality. Therefore, when choosing the cutting edge length, a trade-off needs to be made between the machining depth and the rigidity of the tool.

Number of blades

2-edge: It has relatively poor rigidity and strength, and should be used as little as possible during side milling. However, it is suitable for fisheye hole cutting processing, and the surface roughness of the processed surface is better than that of 4-edge, and the hole diameter size is less likely to be expanded. For non-ferrous metals and soft materials such as aluminum alloys, copper alloys, and plastics, it is recommended to use sharp end mills with two edges.

3-edge: Its rigidity and chip removal performance lie between those of 2-edge and 4-edge. It is ideal for both iron grooves and side milling, but it is not easy to measure. Most three-edge milling cutters are mainly made of aluminum. This is because aluminum is relatively soft in texture and does not have high requirements for processing tools. At the same time, aluminum is a continuous chip. If it cannot be removed in time during high-speed cutting, it will stick to the tool and form mechanical flow, affecting the surface finish of the workpiece. Therefore, three-edge milling cutters are generally used for aluminum.

4-edge or 6-edge: Better rigidity, suitable for face milling, side milling and finish machining, and can adopt a small amount of rapid cutting method. When cutting the side of a finish mill, it is recommended to use a 4-edge or 6-edge end mill.

Materials: Common materials include high-speed steel, hard alloy and ceramics, etc. High-speed steel end mills are suitable for low-speed cutting, while carbide and ceramic end mills are more suitable for high-speed cutting. In large-scale mold processing, to enhance processing efficiency and tool life, carbide end mills are usually selected. For processing high-hardness materials, 4-edge or 6-edge carbide end mills are mostly used.

Coating: Coating can enhance the wear resistance, heat resistance and anti-adhesion of cutting tools, thereby extending the tool life and improving the processing quality. The type of tool coating should be selected based on the type and hardness of the workpiece to be processed. For instance, when processing workpieces such as carbon steel with a hardness below HRC40, the BWTiALN coating can be selected. When processing workpieces such as alloy steel S and tool steel with a hardness of around HRC50, nano-titanium aluminum nitride film -NanoTiAlN coating can be selected. When processing workpieces with higher hardness, the BW TiALN+PLC coating for high-hardness processing can be selected, where the tool shape, hard alloy material and coating are all specially designed for processing high-hardness materials.

The shape of the cutter neck: The shape of the cutter neck of end mills is divided into standard type, long neck type and conical neck type, and can be selected according to the processing depth and shape of the workpiece. The long-neck type and the conical neck type can be processed for deep excavation. When choosing between the two, the interference Angle should be taken into consideration. Meanwhile, compared with the long-neck type, the conical neck type end mill has higher rigidity, which can improve the cutting conditions and achieve better processing accuracy. Therefore, the conical neck type end mill should be chosen as much as possible.