Milling cutters are used on CNC machining center milling machines to process flat surfaces, steps, grooves, formed surfaces, and cut off workpieces. This has a significant impact on the quality of the processed parts. So how to choose a suitable milling cutter?
The milling cutter used in CNC machining should be made of all hard alloys. Generally, white steel material is used on milling machines. The hardness of white steel milling cutters and hard alloy milling cutters is relatively soft. Hard alloy milling cutters have good thermal hardness and wear resistance, but their impact resistance is poor, and the blade will shatter if dropped randomly. Hard alloy is a material made by powder metallurgy, with a hardness of around 90HRA and a thermal conductivity of around 900-1000 degrees.
1. Number of milling cutter teeth
When selecting a milling cutter, consider its number of teeth. For example, a coarse tooth milling cutter with a diameter of 100mm only requires 6 teeth, while a dense tooth milling cutter with a diameter of 100mm can have 8 teeth. The size of the tooth pitch will determine the number of cutting teeth that participate in milling, affecting the smoothness of cutting and the requirements for the cutting rate of the machine tool.
2. Debris storage tank
Coarse tooth milling cutters are mostly used for rough machining because they have large chip holding slots. Assuming that the chip holding groove is not large enough, it will cause difficulty in curling chips or exacerbate conflicts between chips and the tool body or workpiece. At the same feed speed, the cutting load per tooth of the coarse tooth milling cutter is greater than that of the dense tooth milling cutter.
3. Cutting depth
During precision milling, the cutting depth is relatively shallow, usually ranging from 0.25-0.64mm. The cutting load per tooth is small (about 0.05-0.15mm), and the required power is not large. It is possible to choose a dense tooth milling cutter and choose a larger feed rate.
4. Application of rough milling
When carrying out heavy load rough milling, excessive cutting force can cause vibration in machine tools with poor rigidity. This vibration can cause the carbide blade to collapse and shorten the tool life. Choosing a coarse tooth milling cutter can reduce the demand for machine tool power.