What is the major load used in the Rockwell C Scale?

In the Rockwell C Scale, the major load used is 150 kg. The Rockwell hardness test is a common method of measuring the hardness of materials, particularly metals. This scale utilizes a diamond indenter to penetrate the surface of the material under a specified load.

The major load of 150 kg is crucial because it produces sufficient pressure to measure hardness in harder materials without causing excessive deformation. The depth of indentation left by the indenter is then measured, and the Rockwell hardness number is determined based on that depth.

Understanding the specific load used in different Rockwell scales is essential for accurate hardness testing and comparison between materials. Other loads, like 100 kg or 200 kg, are used in other Rockwell scales (like B or E), which are suitable for softer materials or varying types of testing. However, for the specific application of the Rockwell C Scale targeting harder materials, the use of 150 kg is the established standard.