Which non-destructive testing methods are commonly used for welds?

• A. Visual inspection (VT), radiographic testing (RT), and ultrasonic testing (UT)
• B. Destructive bending tests only
• C. Hardness testing of welds only
• D. Visual inspection only

Answer: (B)

Non-destructive testing of welds focuses on assessing quality without damaging the weld. The most widely used methods are visual inspection to judge surface condition and geometry, radiographic testing to reveal internal flaws with X-ray or gamma-ray imaging, and ultrasonic testing to detect internal discontinuities using high-frequency sound waves. In practice, other non-destructive methods such as magnetic particle testing and liquid penetrant testing are also employed to catch surface and near-surface defects. These approaches are non-destructive, so they don’t compromise the weld’s integrity, unlike destructive bending tests or hardness tests that can alter or damage the weld. Visual inspection alone can miss internal issues, and relying on any single method isn’t enough to fully evaluate weld quality, which is why a combination of non-destructive techniques is standard.