What is hard turning?
Hard turning refers to the process of using hardened steel turning as a method of final or precision machining. Hardened steel typically refers to workpiece materials that have martensitic structures after quenching, with high hardness, strength, and little plasticity.
When the hardness of hardened steel exceeds 55HRC, its strength is usually around 2100-2600N/mm2. Typically, the workpiece has undergone rough machining before heat treatment and quenching, with only precision machining being performed in the quenched state.

What is grinding?
Grinding is one of the most widely-used material removal methods, which refers to the process of using abrasives and grinding tools to remove excess material from the workpiece.

So, what are the advantages of turning process compared to grinding process?
1. Lower initial investment;
2. More flexible processing;
3. Higher processing efficiency;
4. Better surface roughness;
5. Higher overall machining accuracy.

Halnn Star Products BN-S20, BN-S200, BN-H11, BN-H20, BN-H05, BN-H10, BN-H21, BN-H05 C20, BN-H10 C20, BN-H21 C20.

Halnn CBN inserts can fully achieve stability, higher processing efficiency, lower cost, and roughness requirement of Ra0.8 or less. Additionally, Halnn's chip breaker, wiper design, and coating solutions can further improve processing quality and extend tool lifespan.

Halnn CBN inserts are widely used in hard turning application.

Let’s show a project case of Halnn CBN tool hard turning.
Case 1: Machining of automobile gearbox gear shaft.

Result: Compared to abroad PCBN cutting tools, Halnn BN-H200 cutting tools have an increased lifespan of 45%.

Case2. Halnn BN-H21 Tool for heavy Interrupted Finishing of Gear End Faces
When there are a group of holes on the gear end face, the processing will cause strong impact on the tool, which belongs to the strong interrupted machining condition. Halnn's superhard BN-H21 is the grade specifically for heavy interrupted machining. An example of a processing case is as follows:

Result: Compared to a certain brand of PCBN cutting tool, Halnn’s BN-H21 has increased its lifespan by five times and there is no broken or fracture during heavy interrupted processing.