# X-Ray Testing of Steel Welds

> X-ray testing finds cracks, porosity and lack of fusion inside structural steel welds without cutting them. See a girder example and the checklist record.

Canonical: https://superwise.site/glossary/x-ray-testing/
Last updated: 2026-11-01

A non-destructive test that passes X-rays through a steel weld onto film to reveal cracks and voids inside it.

## What is X-Ray Testing (Radiography NDT)?

X-ray testing, or radiographic testing, is a [Non-Destructive Testing](https://superwise.site/glossary/non-destructive-testing/) (NDT) method used mainly on large steel structures such as bridges and high-rise frames. A technician passes X-rays through a finished thick steel weld onto photographic film. Internal cracks, gas porosity and lack of fusion, which the eye cannot see, show up as dark spots on the developed film.

## Practical example

Before a steel bridge girder is lifted off the ground, the [QA](https://superwise.site/glossary/quality-assurance-quality-control/)/QC inspector orders X-ray testing on the main splice weld joining two 50 mm steel plates. The film shows a large void deep inside the weld. The welder must grind out the whole defective section and weld it again, so that the bridge does not fail under traffic loads.

## In SuperWise

In SuperWise a weld inspection can be built as a checklist with yes or no, number, photo and signature fields, so the inspector can record the result and add a photo of the film. Set as the finish checklist of the welding task, with the checklist enforced, it must be approved before the task can be marked complete.

[Quality and safety checklists](https://superwise.site/features/construction-quality-safety/)

## Related terms

- [Non-Destructive Testing (NDT)](https://superwise.site/glossary/non-destructive-testing/)
- [Quality Assurance / Quality Control (QA/QC)](https://superwise.site/glossary/quality-assurance-quality-control/)

## Related
- [Non-Destructive Testing (NDT)](https://superwise.site/glossary/non-destructive-testing/)
- [Quality Assurance / Quality Control (QA/QC)](https://superwise.site/glossary/quality-assurance-quality-control/)
- [Quality and safety checklists](https://superwise.site/features/construction-quality-safety/)