Foundrax MD Alex Austin explained the background to Brinell testing late in 2019 in an article for Materials Today, an abridged version of which is reproduced here:
Why hardness matters
Measuring the hardness of metal is a critical step in the manufacturing process. Cross-industry recognised standards and accurate testing are vital for safety and efficiency but also to understand materials’ behaviour.
For more than a century the Brinell scale and hardness test have been widely used to determine the hardness value of steel, cast iron and aluminium components.
Brinell hardness test – a brief history
More than 100 years ago, Swedish engineer Johan August Brinell created a formula and procedure for determining the hardness of a metal and he showcased his prototype at the 1900 Paris Exposition, where talking films and escalators were seen for the first time. The Brinell test became established as the first universally accurate method of testing the hardness of materials.
While basic scratch tests originally determined materials’ (specifically minerals’) hardness and were measured against Mohs’ scale, Brinell’s machine shed new light on determining the quality of manufactured materials.
He standardised the measurement of metal by pressing a steel ball into the surface of a specimen. He used a known load quantity to deform the material with an indentation and from this he acquired data from which hardness could be calculated.
Further developments in measuring material hardness by Knoop, Rockwell and Vickers Ltd came about in the following decades. While each test expresses its results using a unique measurement, the empirical value of the Brinell method lies in the ability to test rough-surfaced, non-homogeneous components like iron and steel castings. Moreover, the ability to choose test forces and ball diameters means it has a wide variety of applications.