What case depth is
Case depth is how deep below the surface the steel stays above a hardness threshold before dropping to core hardness.
Too shallow and the skin wears through to soft metal fast; too deep and it can get brittle or waste time/cost.
How it is measured
- Effective case depth — a cross-section hardness traverse from the surface inward to a set value (e.g. 550 HV).
- A cross-section microstructure check confirms the hardened layer.
How it is controlled
Carburizing is controlled by furnace temperature, time and carbon potential.
Induction is controlled by frequency, power and time.
We sample case depth plus surface/core hardness and can issue results with the job.
FAQ
How do I specify case depth?+
Give a depth range at a hardness threshold, e.g. 0.3–0.5 mm at 550 HV; we control the process to hit it.
Does measuring it cut the part?+
Accurate effective case depth uses a cross-section sample; surface hardness can be checked non-destructively.
Is a hard skin alone enough?+
No—depth matters too. A hard but shallow case wears through to soft metal quickly.
