The usual way to specify carburized and induction cases: distance from the surface to the point where a microhardness traverse reaches 50 HRC (513 HV), unless another value is called out. It is shallower than total case depth and correlates better with load capacity. Drawings write it as ECD with a range, such as 0.75 to 1.0 mm.
Traverse hits 513 at 0.034, so effective case depth is 0.034 and total runs out near 0.050.
Also heard as
- ECD
- effective case
Related terms
Case depth
Thickness of a hardened surface layer, measured from the surface to a specified hardness or structure.
Microhardness
Hardness measured with very small loads under a microscope, used for thin cases and individual phases.
Carburizing
Diffusing carbon into the surface of low-carbon steel at high heat, then quenching for a hard case.
Induction hardening
Heating only the surface of a steel part with an alternating magnetic field, then quenching for a hard case.