Brinell/ ASTM E10
The test consists of applying a prescribed load, usually between 500kg and 3000kg for a specified time (10-30 seconds) using a 5 or 10mm diameter tungsten carbide ball on the flat surface of a metal sample. This testing is widely used in the forging and casting industry.
Rockwell and Superficial Rockwell are the two types of Rockwell hardness testing that are widely used. The differences between the two are the minor and major loads applied to the specimen. The indenter used may be a diamond cone or a hardened tungsten carbide ball, which alongwith the force applied determines the hardness scale.
Knoop & Vickers(Micro)/ASTM E384
These are the standard test methodsfor Microindentation Hardness of Materials. Knoop indenter has a rhombic-based pyramidal diamond with an included longitudinal angle of 172° 30´ and an included transverse angle of 130° 0´. The narrow, elongated indenter makes it ideal for testing materials with steep hardness gradients. Only the long diagonal of the indentation is measured for calculations. Knoop is widely used for microindentation hardness testing in USA.
Vickers has a square-based pyramidal shaped indenter with face angles of 136°. Both the diagonals of the indentation are measured for calculations.