Challenges in Ball Screw Machining
Ball screws are commonly made from materials such as 42CrMo and GCr15. After heat treatment, their hardness typically ranges from HRC58-62, with stringent geometric tolerances and dimensional accuracy requirements. Traditional cutting tools struggle to meet these demands.
Polycrystalline Cubic Boron Nitride (PCBN) tools excel in machining ferrous metals due to their high hardness, thermal stability, and chemical inertness. These qualities make PCBN tools the ideal choice for efficient hard turning of ball screws, replacing grinding processes.
Tool Requirements for Ball Screw Machining and the Advantages of PCBN Tools
1. High Hardness and Wear Resistance
After heat treatment, ball screw materials have a hardness of HRC58-62, whereas conventional carbide or ceramic tools often fail due to insufficient wear resistance.
Moresuperhard’s PCBN tools are engineered with refined CBN grains and superior manufacturing processes, ensuring exceptional wear resistance, thermal stability, and red hardness at elevated temperatures.
- Applicable Materials: 42CrMo, 20CrMnTi, 20CrNiMo, and other ferrous metals.
- Performance: Capable of machining workpieces with hardness exceeding HRC60, offering tool life 3-5 times longer than carbide or coated tools, and reducing tool wear or chipping caused by high temperatures.
2. High Precision and Dimensional Consistency
Ball screws require strict geometric tolerances and dimensional accuracy, which are difficult to achieve with conventional tools.
Moresuperhard’s PCBN inserts enable high-precision and high-finish machining by replacing grinding processes with hard turning, ensuring:
- Excellent surface finish and dimensional consistency.
- Reduced geometric errors.
- Multi-edge, indexable design for minimized tool setup time and fewer tool changes, improving overall efficiency.
3. Exceptional Impact Resistance
Thread removal in ball screw machining involves interrupted cuts, where conventional tools are prone to chipping.
Moresuperhard’s integral PCBN inserts feature a metal binder that enhances impact resistance, making them more durable and reliable, even in demanding interrupted cutting conditions, outperforming imported tools.
4. High-Speed Cutting Capability
PCBN tools are ideal for automated mass production of hardened steel components, capable of withstanding high temperatures, high speeds, and interrupted cuts.
- Efficiency: Moresuperhard’s PCBN inserts achieve cutting speeds up to 200 m/min when turning hardened steel, significantly boosting productivity.
Case Study: PCBN Tools for Ball Screw Machining
Rough Turning of Ball Screw Threads
- Process: Rough turning of ball screw thread grooves.
- Material: 20CrMnTi, HRC58-62.
- Recommended Tool: SNGN090408.
- Cutting Parameters:
- Cutting speed (Vc): 150-190 m/min.
- Depth of cut (ap): 0.2-0.3 mm.
- Feed rate (f): 0.15 mm/rev.
- Advantages:
Moresuperhard’s PCBN inserts offer 4x longer tool life and 1.5x higher processing efficiency than a leading ceramic tool brand.
Versatile Applications of PCBN Inserts
1. Cast Iron Components
It is suitable for rough and finish machining of brake discs, drums, flanges, transmission housings, engine blocks, and cylinder heads, supporting both continuous and interrupted cutting conditions.
2. Hardened Steel Components
Ideal for machining ball screws, bearings, drive shafts, gears, crankshafts, and similar parts, with excellent bending strength and adaptability to high-speed cutting.
3. Wear-Resistant Components
Designed for industrial pumps, hammer crushers, slurry pumps, and cylinder liners, Moresuperhard’s PCBN inserts offer superior wear resistance. They support heavy material removal while extending tool life.
Conclusion
Moresuperhard’s PCBN tools are an outstanding solution for machining ball screws and other high-hardness, high-precision components. Their exceptional performance and reliability deliver higher productivity and economic benefits for users, regardless of the complexity or scale of the application.
