Determination of test cycle sensitivity coefficients for the Rockwell HR45N hardness scale

This article describes work carried out to determine test cycle sensitivity coefficients for the Rockwell HR45N hardness scale. Sensitivity coefficients were determined for the preliminary-force, total-force and recovery-force dwell times. The work was carried out in 2017 at the National Institute of Standards and Technology (NIST) in Gaithersburg, USA.