硬さの単位hrcとは？ | オーエスジー

There are various units that express the properties of metal materials, and it is important to check their numerical values before processing metal materials.
It is also important to select a cutting tool that matches the hardness of the workpiece material.
Among steel materials, the units of materials to be processed by taps and drills include HRC, which represents the hardness of relatively hard materials, and HB, which represents the hardness of relatively soft ~ mediumly soft materials.
HRC is a unit of hardness tested using C-scale steel balls used for hard metals as an indenter in the Rockwell hardness test.
The HRA is a test using the A scale.
Conversion tables with other hardness units are introduced below.