Which industry is mentioned in relation to the oil-and-whiting LPI usage?

• A. Automotive parts
• B. Railway parts
• C. Aerospace components
• D. Ship hulls

Answer: (B)

In liquid penetrant inspection, the oil-and-whiting approach uses an oil-based penetrant followed by a dry white developer (whiting) to reveal surface-breaking flaws with high contrast. This combination is often described in contexts involving railway components because railroad parts—like rails, wheels, and other large steel pieces—require reliable, sensitive detection of surface defects and have a long history of using penetrant methods in maintenance and inspection programs. The railway industry’s emphasis on safety-critical, surface-breaking flaws makes it a typical example where this oil-and-whiting method is mentioned.