Hardness, as applied to most materials, and in particular metals, is a valuable, revealing, and commonly employed mechanical test that has been in use in
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"Paramount to accurate and reliable Rockwell hardness results is ensuring that the operators and the methods used are following proper test technique and practice.
Failure to properly prepare and execute a Rockwell hardness test can result in compromised test data or false readings,"
"Daily indirect performance verification of the testing instrument is also important; the scales being used should be verified using standardized test blocks or coupons.
Five total readings should be made in the verification process; the measured values must fall within the tolerance stated on block and the block certificate."
"ASTM recommends annual maintenance and verification of a Rockwell tester and more frequent verification under heavy use or extreme conditions. Verification should be performed by an accredited verifying agency and the report should follow and reference ASTM E18 Rockwell test method."