Does it ever cross your mind how the assessment of a material hardness test is interpreted? Concluding a hardness test using a popular method like the Brinell hardness test requires measuring the indentation left on the material surface by the load applied. Though several other hardness testing methods are available, the Brinell hardness test and how to read and represent its values are why we’ve written this guide. So, hop on the ride, and let’s dig deeper.
I. Why Use the Brinell Hardness Value?
The critical part of the Brinell hardness and the reason so many quality assessment professionals prefer it is primarily because they can adjust the measurement load based on the material under examination. Meaning that if a softer material requires a hardness test, a load reduction can accommodate this test. Furthermore, the Brinell hardness value is often adaptable because it meets standard quality regulations of the ASTM and ISO recommendations. It is likewise easily convertible into ultimate tensile strength. But its choice all depends on the material under examination.
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II. How do you Read a Brinell Hardness Number?
A critical aspect of the Brinell method of testing is the process of reading the Brinell hardness number, but the question is, how is it done? Since the material type determines the load, it implies that the different materials often fall under a specific material hardness scale, also known as the Brinell hardness number. This Brinell hardness number then determines the load applied to a material. For instance, a material like mild steel may have a Brinell hardness number of 130. Checking the range on the load chart may reveal that for materials between 100-200 Brinell numbers, the applicable test load is 3000kg. This means the indenter applies a 300kgf load during the test. This is how to read a Brinell Hardness Number.
III. Examples of How to Represent and Read Brinell Hardness Value
Representing the Brinell hardness value often requires some critical components. These components include the numeric hardness value, the alphabet HBW (representing Hardness according to Brinell), ball diameter in mm, test load to be applied in kgf, and the dwell time of test load (typically 10-15 mins under practicable circumstances). These are the components of presenting and reading a Brinell hardness number. An example of a Brinell hardness number could be in the form of 200 HBW 5/250/15. You can read this number as 200 – the hardness value, HBW – Brinell with a tungsten carbide ball, 5 – the diameter of the ball, 250 – the load applied in kgf, and 15 – the dwell time in seconds required for the test.
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IV. What does a High Brinell Hardness Number Mean?
The Brinell hardness number represents the hardness of a material or metal. However, higher or lower Brinell hardness numbers often indicate the load required to cause a measurable indentation on the material surface. In essence, a higher Brinell hardness number means a harder material or metal. It also means that the higher the hardness number, the higher the probability of applying a higher load, which also translates to a longer dwell time for the applied load.
V. What is the Brinell Hardness Number for Copper?
The Brinell hardness number represents the hardness of a material or metal. However, higher or lower Brinell hardness numbers often indicate the load required to cause a measurable indentation on the material surface. In essence, a higher Brinell hardness number means a harder material or metal. It also means that the higher the hardness number, the higher the probability of applying a higher load, which also translates to a longer dwell time for the applied load.
VI. What is the Brinell Hardness Number for Aluminum?
Aluminum can be of two varying types: pure aluminum or hardened aluminum. Pure aluminum might be a little softer than hardened aluminum. For that reason, its hardness number is often slightly lower. The hardness number for pure aluminum is fifteen, while the hardness number for hardened aluminum is seventy-five.
Conclusion
In a nutshell, the Brinell hardness test records the diameter and depth of the indentation caused by a ball-shaped indenter, with the indenter pressed into a material’s surface. You can use the recorded value to calculate the Brinell hardness number. Conclusively, the hardness number for Copper and aluminum is thirty-five and seventy-five, respectively (hardened aluminum). If you follow the steps outlined in this post, accurately reading and representing Brinell hardness test values should be very easy.