Hardness Measurement by Rockwell Hardness testing Machine

This method of determining the hardness of a sample complete covers the procedure and calculation using Rockwell hardness testing machine. This is a simple method and the complete procedure for performing this test is described below.

Introduction:

The Rockwell tests constitute the most common method used to measure hardness because they are so simple to perform and require no special skills. Several different scales may be utilized from possible combination of various indenters and different loads, which permits the testing of virtually all metals and alloys from the hardest to the softest.

Experimental Work:

There were three samples in the experiment which were indicated by “Sample A”, “Sample B” and “Sample C”. Sample C was provided to me for hardness measurement. The apparatus required for this experiment is given below;

• Rockwell Hardness Testing Machine


• Indenter


• Sand paper ( If sample surface is not clean)


• Sample

Procedure:

The procedure of the experiment was involved following steps;

• The sample C was provided me to perform the hardness test; the first job was to clean the surface of the sample by sand paper.


• After cleaning the surface of specimen the, the sample was placed upon anvil until the indenter touches the specimen.


• On further raising the anvil , the lever of the machine was raised the spindle of the dial and when the groove on the spindle was coincided with the beveled edge of the spindle housing, the minor load of 10Kg had been applied.


• The dial was then set to zero and the major load was applied.


• The dial reading was representing the depth of the indentation produced by the added load, and was taken out as the hardness of the specimen.

Calculations:

Indenter used = Diamond cone

Minor load = 10Kg

Major load = 150Kg

Scale = Black

HRC = = 82.25

HRA = = 39.25