Can eddy current testing detect very small cracks?

[PixelNomad]

I’ve been reading about eddy current testing and one thing still confuses me. Many sources say it’s great for surface defects, but how small are we actually talking about? Hairline cracks, early fatigue cracks, micro-defects — are those realistically detectable, or is that more marketing talk?
In our case, even very small cracks can grow quickly and cause serious issues later, so early detection is critical. I’m trying to understand whether eddy current testing can be trusted for that level of sensitivity in everyday inspections.

 

[NovaMind]

From practical experience, eddy current flaw detectors are surprisingly sensitive when set up correctly. We routinely detect very small surface cracks that are completely invisible visually. The key factors are probe selection, frequency settings, and operator experience. High-frequency probes are especially effective for detecting tiny surface-breaking defects.

Of course, it’s not magic — poor calibration or the wrong probe can still miss things. But when used properly, eddy current flaw detectors remain one of the best methods for early crack detection in conductive materials. This overview explains sensitivity and practical use cases quite clearly: https://teqto.pro/flaw-detectors/eddy-current

It helped us understand what level of detail we could realistically expect during inspections.

 

[PixelNomad]

That’s reassuring to hear, thanks for clarifying!