The Brinell hardness test is used for larger samples in materials with a coarse or inhomogeneous grain structure. This page describes the Brinell hardness test in detail and gives you practical information on how to apply it.
The Brinell hardness test was originally developed in the late 1800s by the Swedish engineer of the same name. He wanted to find a method to control the quality/hardness of steel. His solution was to press a railway wheel-bearing ball into the material and then measure the size of the mark it left. The method proved reliable and in 1900 the Brinell hardness test was officially born.
Today, the Brinell test is performed using a Brinell hardness test unit. The machine presses a tungsten carbide ball into the sample, and then optically measures the diameter of the impression.
Indenter sizes: 1, 2.5, 5 and 10 mm
Loads: From 1 kgf to 3000 kgf
Maximum hardness: 650 HBW
A hardness test for larger samples
As the Brinell hardness test (HBW) indentation leaves a relatively large impression, the Brinell hardness test is better suited to larger samples with a coarse or inhomogeneous grain structure, such as castings and forgings.
Good to know
HBW stands for Hardness Brinell Wolfram carbide. Wolfram carbide (= tungsten carbide) underlines that newer Brinell standards call for the use of tungsten carbide balls, as opposed to the (softer) steel balls previously used (HBS). Values will differ at higher hardness.
APPLICATION OF THE BRINELL HARDNESS TEST
Before performing the Brinell hardness test, you must prepare the surface of the material to be tested.
Before the sample material is placed in the Brinell hardness test unit, it must be either:
Indentation time: 10-15 seconds
Sample thickness ASTM: At least 10 times the indentation depth
Sample thickness ISO: At least 8 times the indentation depth
The most common Brinell hardness test methods
There are a number of common Brinell hardness test methods, with corresponding materials and hardness ranges. Most test methods can be performed on any Brinell hardness testing machine.
The Brinell methods are generally divided into four subgroups (HB30, HB10, HB5, HB2.5), each suitable for a different group of materials.
Each subgroup has the same force/diameter ratio (F/D2)
Measured Brinell hardnesses can only be compared within individual subgroups
* Materials mentioned in the table are examples of typical materials only.
HBW 2.5/187.5: Brinell 2.5 mm tungsten carbide ball and 187.5 kgf load.
HBW 5/750: Brinell 5.0 mm tungsten carbide ball and 750 kgf load.
BRINELL HARDNESS TESTING MACHINES (HARDNESS TEST UNITS)