Ask anyone and they will tell you with certainty which objects are hard and which is not.
This happens to be one of those things that people feel they know.
Therefore, they may not give it a second thought.
If questioned more closely regarding their answer it may prove to be a real head-scratcher.
In case there are any lingering confusions, hardness refers to the varying ability of a given object or material to resist indentation when a force is applied to it and it is usually calculated using the area of the depth of the indentation.
The hardness of material needs to be categorized as a character as opposed to one of its properties.
Of all the tests used to measure hardness, the Rockwell Test happens to be one of the simplest and easiest to perform, which is why it is the most frequently used method.
The accuracy of its results is also generally unquestionable.
There are certain situations where it may not be usable but for the most part, this test can be used for all kinds of materials or substances.
Simple yet Complex
The Rockwell Test does its job using a very simple concept.
It includes applying a certain amount of fixed force on the material being tested and then removing the load to inspect the depth of the indentation made on the material.
Generally, the load is provided via a small indenter such as a diamond.
It may seem very simple, and the concept is simple, but practically the testing procedure is more complicated than it lets on.
One factor that adds to this complexity is the differences between individual bits of metal.
This is one of the reasons why there are thirty individual Rockwell Tests.
They are similar but they tend to utilize different loads and such for the tests.
Not all Tests are appropriate for a certain material.
The material and its properties must be considered when selecting the proper test.
This test is perfect for those who are as yet amateurs and are inexperienced with testing hardness.
On top of that, the Rockwell Test does not generally leave much of a mark and the material is left unblemished.
Moreover, its accurate testing results only add further credibility to this test.
If done right, this test should be enough to test the hardness of almost any material, hard or otherwise.