Automotive intermediate shafts require dependable finishing after carburizing and hardening, particularly where automated production demands predictable cycle times, controlled dimensions, and repeatable surface quality. UHD Composite Brazed CBN Inserts provide a precision-turning solution for this small-stock finishing operation on hardened steel components.
In the documented application, the UPN602 C06 DNGA150408 Composite Brazed CBN Insert was configured for dry, continuous finishing of both outside diameters. The solution combines insert structure, brazing consistency, edge-scale design, and validated cutting parameters to support stable machining at higher cutting speeds.
An automotive intermediate shaft is a critical drivetrain component. During its final precision-turning stage, dimensional accuracy, surface condition, and part-to-part consistency directly influence downstream assembly requirements. The workpiece in this application was made from 20CrMnTiH carburized and hardened steel, with a hardness of HRC 58–62.
The operation involved a small finishing allowance of approximately 0.2–0.5 mm. At this stage, conventional tooling can face surface fluctuation, visible tool marks, limited edge life, and unstable size control. These issues become more consequential in continuous and automated production, where frequent tool changes or variable machining results can interrupt the planned production rhythm.
Finishing with limited stock removal can be sensitive to vibration, leading to tool marks and variation in surface appearance.
Short edge life increases replacement frequency and can reduce machine availability in high-volume production.
A restricted cutting speed can limit output from a production line even when machine capability is available.
For automated machining, stable dimensions over repeated cycles are as important as the performance of a single part.
UHD selected a composite brazed CBN insert configuration for dry continuous turning. The insert was introduced through a controlled process of baseline comparison, speed adjustment, batch validation, and automated-line verification.
| Item | Application Configuration |
|---|---|
| Insert grade / type | UPN602 C06 composite brazed CBN insert |
| Insert designation | DNGA150408 |
| Workpiece material | 20CrMnTiH carburized hardened steel, HRC 58–62 |
| Machining operation | Finish turning of both outside diameters; continuous cutting |
| Cutting environment | Dry cutting |
| Cutting speed (Vc) | 200 m/min |
| Depth of cut (ap) | 0.25 mm |
| Feed rate (f) | 0.08 mm/rev |
For hardened steel precision turning, insert performance depends on more than CBN material selection. The connection between the CBN cutting layer and carbide substrate, the geometry of the cutting zone, and the repeatability of the manufacturing process all influence behavior under production conditions.
Against the previously used Japanese-brand CBN insert under the same application conditions, the UHD solution achieved the following documented operating results:
| Performance Indicator | Previous Insert | UHD Composite Brazed CBN Insert |
|---|---|---|
| Cutting speed | 120 m/min | 200 m/min |
| Machining cycle time | 7 s/part | 3 s/part |
| Tool life | 150 parts/edge | 200 parts/edge |
Based on the recorded comparison, machining efficiency increased by approximately 57%, while tool life increased by approximately 33%. Surface quality remained more stable, and dimensional consistency was easier to manage for batch production.
The insert upgrade was implemented without changes to the machine structure. Instead, UHD followed a coordinated validation approach focused on practical production conditions:
This application offers a practical reference for automotive shafts, bearing and gear components, and other hardened steel parts requiring high-consistency finishing. Results in any production environment depend on the workpiece condition, machine rigidity, clamping, stock allowance, toolholder arrangement, and selected cutting parameters.
Selection guidance: For small-stock finishing of hardened components, evaluate cutting-edge structure and process stability alongside CBN grade. A higher cutting speed should be validated through controlled trials rather than applied as an isolated parameter change.
Tell us your workpiece material, hardness, machining operation, and current cutting conditions. UHD can recommend a suitable CBN insert configuration and cutting parameters for your application.
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