Hairline cracks are easy to miss, but under a UV light they show up clearly. We use UV (fluorescent dye penetrant) inspection to find surface cracks, porosity, and leaks in engine and drivetrain components, including aluminum and other non-magnetic parts that Magnaflux can’t test. The dye seeps into any crack and glows under UV light, so you know whether a part is safe to reuse or needs repair or replacement before it goes back into service. Testing is done in our shop.