Which test could be used to indicate an approximation of hardness?

Which test could be used to indicate an approximation of hardness?

• A. tensile test
• B. impact test
• C. radiographic examination
• D. magnetic particle test

Answer: (A)

Hardness reflects how well a material resists local plastic deformation, and you can estimate it from other mechanical properties that relate to strength. A tensile test provides yield strength and ultimate tensile strength, which are known to correlate with hardness for many metals. By using these strength values, engineers apply established empirical relationships to estimate hardness values, giving you a practical approximation without performing a dedicated hardness test. Different materials have different relationships, so the estimate is approximate, but it’s the most direct way among common tests to infer hardness. Radiographic examination and magnetic particle testing look for internal or surface defects, not deformation resistance, so they don’t offer a reliable hardness estimate. An impact (toughness) test measures energy absorption and brittleness, which also doesn’t directly indicate hardness.

Hardness reflects how well a material resists local plastic deformation, and you can estimate it from other mechanical properties that relate to strength. A tensile test provides yield strength and ultimate tensile strength, which are known to correlate with hardness for many metals. By using these strength values, engineers apply established empirical relationships to estimate hardness values, giving you a practical approximation without performing a dedicated hardness test. Different materials have different relationships, so the estimate is approximate, but it’s the most direct way among common tests to infer hardness.

Radiographic examination and magnetic particle testing look for internal or surface defects, not deformation resistance, so they don’t offer a reliable hardness estimate. An impact (toughness) test measures energy absorption and brittleness, which also doesn’t directly indicate hardness.