Rockwell hardness

noun

Rock·​well hardness

ˈräˌkwel-,

-kwəl-

: the hardness of a metal or alloy measured by an apparatus in which a diamond-pointed cone is pressed into the metal to a standard depth to determine the relative resistance to penetration as indicated automatically by a number on a dial

Word History

Etymology

after Stanley P. Rockwell, 20th century American metallurgist

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