The Rockwell hardness test is a widely used method for determining the hardness of a material, especially in the field of metallurgy. There are different types of Rockwell hardness test methods, which each have different scales and procedures. In this article, we will focus on the major and minor load in the standard Rockwell hardness test and understand their significance.
What is Rockwell hardness test?
The Rockwell hardness test is a method of measuring the hardness of a material by indenting it with a diamond or tungsten carbide ball. The depth of the indentation is measured, which indicates the hardness of the material. The test is non-destructive, quick and easy to perform, making it an ideal method for industrial testing. It is widely used in metallurgy, materials science, and manufacturing industries.
What is major load in Rockwell hardness test?
The major load is the initial load applied to the material during the Rockwell hardness test. It is typically set to a value between 60kg and 150kg, depending on the hardness of the material being tested. The major load is used to overcome the surface of the material and make a preliminary indentation. Once the preliminary indentation is made, the major load is removed, and the minor load is applied. The indentation depth is then measured.
What is minor load in Rockwell hardness test?
The minor load is the secondary load applied to the material in the Rockwell hardness test. It is typically set to 10kg or 3kg, depending on the test scale being used. The minor load is used to maintain the position of the penetrator during the measurement of the indentation depth. The Rockwell hardness number (HR) is calculated from the difference between the depth of the preliminary indentation made by the major load and the depth made by the minor load. The minor load ensures accuracy and repeatability of the test results.
Conclusion
In conclusion, the major and minor loads are critical components of the Rockwell hardness test. The major load makes a preliminary indentation, and the minor load measures the depth of the indentation. The depth of the indentation is used to calculate the Rockwell hardness number, which indicates the hardness of the material. The Rockwell hardness test is a widely used method in the metallurgy and manufacturing industries, and understanding the significance of major and minor loads is important for accurate testing and consistent results.
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