BeginnerTopic 9 of 100Materials & Chemical
Hardness testing
Brinell, Rockwell and Vickers tests indent a material to measure hardness.
In depth
Indentation tests measure hardness: Brinell (ball, HB), Vickers (diamond pyramid, HV), Rockwell (depth, HRC/HRB), Knoop and Shore (polymers). Hardness correlates with tensile strength (UTS≈3.45×HB MPa for steels) and wear resistance. Quick and almost non-destructive.
Key points
- Load and indenter size
- Microhardness for coatings
- Case depth profiles
ExampleA hardened tool steel measures about 60 HRC.
What is Hardness testing?
Brinell, Rockwell and Vickers tests indent a material to measure hardness.
Why is it important to understand hardness testing?
Hardness tests are quick and non-destructive, so they are widely used for quality control and for estimating strength.
What is the difference between Brinell and Vickers?
Brinell uses a large ball and suits coarse or heterogeneous metals, while Vickers uses a diamond pyramid and works on small areas and thin sections.
Does the test damage the part?
It leaves a small indentation, so it is acceptable for many parts but may not suit critical surfaces or thin parts.
How is Hardness testing used in practice?
Typical applications include checking that a heat-treated gear meets its hardness specification, verifying the hardness of a weld and its heat-affected zone and comparing the hardness of two batches of steel on the shop floor.
What should I learn before Hardness testing?
Study "Mechanical properties" first (topic 8 of 100 in Materials & Chemical). It covers the groundwork this topic builds on.
What are the key points of Hardness testing?
Load and indenter size. Microhardness for coatings. Case depth profiles.
Can you give an example of Hardness testing?
A hardened tool steel measures about 60 HRC.
What comes after Hardness testing?
The next topic is "Tensile testing", which builds directly on this one.
How difficult is Hardness testing?
It is classed as Beginner in Materials & Chemical (topic 9 of 100). It is an entry-level topic. It relies only on basic school mathematics and the ideas introduced earlier in this discipline.