What is HRC, a unit of hardness?
There are various units that express the properties of metals, and it is important to check their values before processing.
It is also important to select a cutting tool that matches the hardness of the workpiece material.
Among steel materials, the hardness units used for materials processed by taps and drills include HRC, which represents the hardness of relatively hard materials, and HB, which represents the hardness of relatively soft to medium-soft materials.
HRC is a unit of hardness tested using the Rockwell C scale, which employs a diamond cone indenter for hard metals.
HRA refers to the Rockwell hardness test using the A scale.
Conversion tables with other hardness units are introduced below.