Knowledge Base
Brinell Hardness Testing: how to calculate
Working out the best and most suitable hardness tests to incorporate in your test and measurement process? Looking to find out more about where the Brinell method is useful and how to calculate the results? Read on for some top tips.
When is the Brinell hardness test used?
Brinell hardness testing is a commonly used method for determining the hardness of metals and alloys.
The Brinell hardness test formula
When measuring hardness using the Brinell method, a hardened steel or carbide ball of known diameter under a known load is forced into the material being tested. The diameter of the indentation is then measured, and the result indicates the hardness of the sample.
There is a formula that can help you calculate the hardness of a material based on the Brinell method. It is:
BHN = 2 P / (π D (D – (D2 – d2)1/2))
Where:
BHN = Brinell hardness number
P = the load on the indenting tool (kg)
D = the diameter of steel ball (mm)
d = measure diameter at the rim of the impression (mm)
Brinell hardness numbers can also often be expressed as BH.
Brinell hardness test charts
The approximate Brinell number for loads are:
| Load (kg) | Brinell hardness number |
| 500 | 26 – 100 |
| 1500 | 80 – 300 |
| 3000 | 160 – 600 |
While the Brinell hardness test is most commonly used to test metals and alloys, it can be used on other materials too.
Typical Brinell hardness numbers include:
| Material | Brinell hardness number |
| Pure aluminum | 15 |
| Copper | 35 |
| Soft brass | 60 |
| Hardened aluminum | 75 |
| Mild steel | 130 |
| Annealed chisel steel | 235 |
| White cast iron | 415 |
| Nitrided surface | 750 |
The Brinell test is often carried out instead of or alongside Rockwell hardness testing and/or Vickers testing. You can find out more about this alternative method in our guide to Rockwell hardness testing.
Hardness testing solutions at Industrial Physics
For all the hardness testing systems you need, whether it’s a hardness pen for testing on the go or a Universal Testing Machine as an addition to your static set up, we’ve got you covered.
With almost 100 years of experience in the testing and measurement sector, we’re the best people to help you find the right machine for the job. If you’d like to hear more about the ways we can help, get in touch.
Was this useful?
Related Products
-
United Testing Tru-Blue Micro VT
The Tru Blue Micro VT is a semi-automatic microhardness tester that offers industry-standard features and high-quality performance when performing Vickers hardness (HV) or Knoop hardness (HK).
-
United Testing Rockwell Hardness Tester Tru-Blue II
The United Testing Tru-Blue II is a bench-top Rockwell hardness tester in 10, 14, 18 and 20 inch vertical test heights - certified to ASTM E18 and ISO 6508, in service at NADCAP-approved heat treatment, fastener and aerospace component manufacturing facilities.
FAQs
-
Brinell hardness testing measures the hardness of materials by pressing a hard ball into the surface and measuring the indentation.
-
It is calculated using the diameter of the indentation and the applied load.
Related Articles
-
Key terms Term Definition Gloss The degree to which a surface reflects light in the specular (mirror) direction. Higher gloss means a shinier surface. Specular reflection Light reflected at the equal and opposite angle to the incident light, as from a mirror. 75 degree geometry The measurement angle used for paper and board gloss, taken…
-
Gloss is the visual perception of shininess, and it comes from the way a surface reflects light. When light hits a very smooth surface, most of it reflects in a single direction, the specular direction, and the surface looks glossy. When the surface is rough or open, light scatters in many directions and the surface…
-
Gloss is a measure of how much light a paper or board surface reflects in the specular, or mirror, direction. A high-gloss sheet reflects light sharply and looks shiny. A matte sheet scatters light and looks dull. In the paper and board industry, gloss is a controlled optical property because it shapes how printed packaging,…
