Which of the following magnetization techniques is not recommended for magnetic particle testing?

Parallel magnetization is not typically recommended for magnetic particle testing because it can lead to reduced sensitivity in detecting surface and near-surface discontinuities. This technique aligns the magnetic field along the same direction as the length of the part being tested, which may not effectively capture indications of flaws that are oriented differently, such as transverse or oblique cracks.

Magnetic particle testing relies on the establishment of a magnetic field that can effectively attract and hold magnetic particles to visible indications of discontinuities. Techniques like perpendicular magnetization or longitudinal magnetization create magnetic fields that are more effective at revealing defects in various orientations. Circle magnetization is especially useful for circular or tubular parts, providing comprehensive coverage for detecting defects around the entire circumference. This allows for a more thorough examination of the material under test.

Using the right magnetization technique is essential for maximizing the detection capabilities of magnetic particle testing, which is why parallel magnetization is generally avoided.