Thread milling is to complete thread milling with the help of the three-axis linkage function of CNC machining center and G02 or G03 spiral interpolation command. The thread milling method itself has certain natural advantages.
Due to the current manufacturing material of thread milling cutters being hard alloys, the processing speed can reach 80-200m/min, while the processing speed of high-speed steel wire cones is only 10-30m/min. Therefore, thread milling cutters are suitable for high-speed cutting and the surface finish of processed threads is also greatly improved.
The thread machining of high hardness materials and high-temperature alloy materials, such as titanium alloy and nickel based alloy, has always been a relatively difficult problem, mainly because high-speed steel cones have a shorter tool life when machining the threads of these materials. However, using a hard alloy thread milling cutter for machining hard material threads is an ideal solution. The machinability hardness is HRC58-62. For thread processing of high-temperature alloy materials, thread milling cutters also show excellent machining performance and unexpected long lifespan. For threaded holes with the same pitch and different diameters, using a tap for machining requires multiple cutting tools to complete. However, if using a thread milling cutter for machining, only one cutting tool can be used. After the tap is ground and the processed thread size is less than the tolerance, it cannot be used anymore and can only be scrapped; When the thread milling cutter is worn and the size of the processed thread hole is less than the tolerance, necessary tool radius compensation adjustments can be made through the CNC system to continue processing qualified threads. Similarly, in order to obtain high-precision threaded holes, using a thread milling cutter to adjust the tool radius is much easier than producing high-precision taps. For small diameter thread processing, especially for high hardness and high-temperature materials, the tap may sometimes break, block the threaded hole, and even cause parts to be scrapped; Using a thread milling cutter, due to the smaller diameter of the tool compared to the processed hole, even if it is broken, it will not block the base thread hole, making it very easy to remove and will not cause parts to be scrapped; By using thread milling, the cutting force of the cutting tool is significantly reduced compared to the tap, which is particularly important for machining large diameter threads. This solves the problem of the machine tool being overloaded and unable to drive the tap for normal machining.The machine clamp blade type thread milling cutter was introduced a year ago, and people have also realized that when machining threaded holes above M20 on a machining center, using a thread milling cutter can significantly reduce processing costs compared to using a tap. However, in recent years, the design and production technology of overall hard alloy thread milling cutters have gradually matured, and a series of products with a complete range of sizes have been developed. For the application of small diameter thread machining, an aviation enterprise needs to process 50 M1.6×0.35 thread drilling holes on an aluminum component. The customer encountered a problem: due to the blind hole, chip removal is difficult, and it is easy to break when using a tap for machining; As tapping is the final process, if the part is scrapped, the significant processing time spent on the part will be completely lost. Finally, the customer selected a thread milling cutter for processing M1.6×0.35 threads, with a linear speed of Vc=25m/min and a speed of S=4900r/min (machine limit), and a feed rate of fz=0.05mm/r per revolution. The actual processing time was 4 seconds per thread, and all 50 workpieces were completed with one tool.
A certain cutting tool production enterprise, due to the general hardness of the cutting tool body being HRC44, it is difficult to use high-speed steel wire taps to process small diameter threaded holes that compress the blade. The tool life is short and easy to break. For M4x0.7 thread processing, the customer chooses a solid carbide thread milling cutter with Vc=60m/minFz=0.03mm/r processing time of 11 seconds/thread, and the tool life reaches 832 threads, with excellent thread finish.
Medium diameter thread machining involves the use of three different sizes of threaded holes, M12x0.5, M6x0.5, and M7x0.5, on aluminum parts to be machined by a certain enterprise, with the same pitch. Previously, three types of taps were required to complete the machining. We are now using a thread milling cutter with cutting conditions: Vc=100m/min, S=8000r/min, fz=0.04mm/r. The processing time for one thread is 4 seconds, 3 seconds, and 3 seconds, respectively. One tool can process 9000 threads. After completing the entire batch of parts processing, the tool has not been damaged yet.
In the large-scale power generation and metallurgical equipment processing industries, as well as the pump and valve processing industries, thread milling cutters have solved the problem of machining large diameter threads, becoming an ideal machining tool with high efficiency and low cost. For example, a certain valve parts processing enterprise needs to process 2 “x11BSP-30 threads made of cast steel and hopes to improve processing efficiency. By selecting a multi chip slot and multi blade machine clamp type thread milling cutter, using cutting parameters of Vc=80m/min, S=850r/min, fz=0.07mm/r, the processing time is 2min/thread, and the blade life is 620 pieces, effectively improving the processing efficiency of large diameter threads.
Thread milling cutters, as an advanced tool that has rapidly developed in recent years, are increasingly being accepted by enterprises and exhibit excellent processing performance, becoming a powerful weapon for enterprises to reduce thread processing costs, improve efficiency, and solve thread processing problems.
Post time: Jul-27-2023