Why is an incorrect hardness value obtained when the indentation is made very close to a preexisting indentation?

Question

Accepted Answer

The region around the indentation will be work-hardened and give an abnormally high reading

Answer

The indentations might overlap and be difficult to measure accurately

Answer

It is only possible to put a single indentation on a specimen

Answer

Indentations which are too close might cause a crack to form

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