As the global automotive industry accelerates its transition to new energy, the three-electric system—comprising the battery, motor, and electronic control unit—has become the core competitive advantage of new-energy vehicles. The precision requirements for machining these components have surpassed the ±0.002 mm threshold, a level that conventional cutting tools can no longer meet. Thanks to their high rigidity, exceptional wear resistance, and multi-axis coordination capabilities, CNC milling cutters are emerging as critical tools for supporting the precision manufacturing of new-energy vehicles, particularly demonstrating irreplaceable value in the machining of three-electric system components.

I. Motor System: A Dual Breakthrough in Cemented Carbide and Superhard Cutting Tools

The relentless pursuit of higher power density and efficiency in new‑energy vehicle motors has driven advances in the machining technologies for key components such as stator cores and rotor shafts. Take Tesla’s Model 3 hairpin‑wound motor as an example: its stator windings require ten layers of tightly packed flat wires, while the surface roughness of the rotor shaft after turning must be kept below Ra 0.4 μm. Zhuzhou Diamond Cutting Tools has developed the SH360 series end mills for machining high‑hardness steels, featuring a PCBN (polycrystalline cubic boron nitride) substrate paired with a TiAlSiN coating. These tools can sustain continuous cutting at a feed rate of 0.1 mm on materials up to 60 HRC, with tool life three times that of conventional cemented carbide.

In the field of SiC (silicon carbide) power device manufacturing, Shangao Tools has introduced a diamond‑coated milling cutter that, thanks to nano‑scale grain‑control technology, boosts coating hardness to 4,200 HV, effectively addressing the challenges posed by SiC’s high brittleness and susceptibility to chipping. After adopting this tool, a leading motor controller manufacturer saw its yield for micro‑hole machining rise from 78% to 99.2%, while reducing per‑part machining time by 40%.

II. Battery System: Precision Forming of Aluminum Alloy Die-Cast Components

After adopting an integrated die-casting process for new-energy vehicle battery trays, weight is reduced by 30%, while placing higher demands on machining accuracy. The battery frame produced on Dongfeng Motor’s 16,000-ton die‑casting press must maintain a flatness tolerance of ±0.05 mm within a 2,000 mm × 1,500 mm area. Meanwhile, Kobelco Seio’s ultra-fine-grain milling cutter with a 0.3 μm grain size, paired with an ATX superhydrophobic coating, reduces cutting forces by 30% and enables a cutting speed of 7,000 m/min when machining 6061 aluminum alloy, delivering a 25% efficiency gain compared to conventional tools.

For the machining of irregular grooves on battery module end plates, Rijin Group has developed a composite-coated ball‑nose milling cutter. Featuring a gradient coating design, it incorporates a 0.5‑μm diamond layer at the cutting edge and an AlTiN transition layer in the middle, ensuring both exceptional wear resistance at the tip and improved chip evacuation. After implementation by a leading battery manufacturer, the machining time per groove was reduced from 45 seconds to 28 seconds, and tool‑change frequency dropped by 60%.

III. Electrical Control System: The Pinnacle of Micro‑Precision Manufacturing Technology

The widespread adoption of intelligent driving systems has propelled the manufacturing of sensors such as LiDAR and millimeter-wave radar into the nanoscale era. By 2025, domestic LiDAR installations are expected to exceed one million units, with their housings requiring precision machining of complex cavities that meet dimensional tolerances of ±0.005 mm. Hua Rui Precision’s Qilin series of high‑temperature alloy cutting tools, featuring HR7240 cemented carbide and an AlCrN coating deposited via vapor‑phase deposition to a thickness of 0.8 μm, can achieve radial runout control within 0.02 mm on Inconel 718 material—making them ideally suited for the rotor‑mirror machining of the RoboSense M3 LiDAR.

In the field of chip‑package substrate machining, Xiamen Jinlu has developed a micro‑diameter drill‑mill composite tool with a minimum diameter of 0.1 mm. Through an optimized helical‑groove design, it keeps chip‑breaking lengths within 0.3 mm, thereby addressing the challenge of microcracking in ceramic substrate processing. After adoption by an IGBT module manufacturer, product yield improved from 82% to 95%, and single‑line production capacity increased by a factor of 1.8.

IV. Technological Collaboration: Deep Integration of Cutting Tools and Manufacturing Processes

Breakthroughs in the machining of new‑energy vehicle components depend not only on innovations in cutting‑tool materials but also on the comprehensive optimization of the entire process system. The Shanghai Tool Factory has developed a composite forming tool that combines a PCD superhard insert with a carbide shank via mechanical clamping, enabling both roughing and finishing of crankshaft main journal bearings in a single setup and reducing the cycle time from 12 minutes to 7 minutes.

At a five-axis machining center, Han’s Laser has developed the “Jingyou Curved Surface” technology, which, through a dynamic tool-path compensation algorithm, reduces the surface‑form machining error of battery trays from ±0.1 mm to ±0.03 mm. Combined with Kobelco Seiko’s 0.3‑mm micro‑diameter milling cutter, this technology enables stress‑free machining of the battery housing for BYD’s Seal model, increasing the housing’s fatigue life by 40%.

Conclusion

The explosive growth of the new‑energy vehicle industry is reshaping the technological frontiers of the cutting‑tool sector. From PCBN ultra‑hard materials to nano‑coating technologies, and from micro‑diameter machining to five‑axis simultaneous machining, the technology‑iteration cycle for CNC milling cutters has been shortened to just 18 months. Industry forecasts project that by 2028, the market for specialized tools used in new‑energy vehicles will exceed RMB 12 billion, accounting for 65% of the entire automotive tool market. In this wave of technological transformation, companies that master the core tool‑technology value chain will shape the competitive landscape of precision automotive manufacturing over the next decade.