This Brinell test diameter conversions table enables operators of Brinell hardness testing machines to take the diameter of an indentation made by the machine (having determined the diameter as accurately as practicable by using a suitable Brinell microscope such as the ‘BRINscope Duo’) and, having selected the column of data appropriate for the indenter size and force, read across from the diameter to the Brinell number.
Download a pdf of the conversion table below
BRINELL DIAMETER TO HARDNESS CONVERSION TABLE
NOTES FOR USE OF FOUNDRAX BRINELL HARDNESS CONVERSION TABLES
Equivalents are approximate and must be used with caution
HBW 10/3000 means:
| HBW | Hardness Brinell Wolfram (Tungsten Carbide) |
| Ball diameter | 10 |
| Test force | 3000 |
The force is expressed in Newtons which have been converted from kgf. at 1kg=9.807N.
The actual force used is 29 420N which is the same as 3000kgf and the figure 3000 is now known as the load symbol.
When testing at HBW5/750 note the indentation diameter and read off the HBW value in the column to the left.
When testing at HBW10/500, HBW10/1000 or HBW10/3000, note the indentation diameter and read off the HBW value in the appropriate column
It is important that the correct F/D² index (where F is the load symbol and D is the diameter of the ball indenter in mm) is used for any particular test
| Ferrous metals use | F/D² = 30 |
| Copper, copper Alloys, Aluminium Alloys use | F/D² = 10 |
| Aluminium use | F/D² = 5 |
Examples of Load symbol and ball diameter ratios:
f/D2 = 30 . HBW10/3000 . HBW5/750 . HBW2/120
f/D2 = 10 . HBW10/1000 . HBW5/250
f/D2 = 5 . HBW10/500
The material being tested must be at least 8 times as thick as the depth of the Brinell indentation.
In order to achieve the most accurate results it is necessary to have as large as possible an indentation compatible with the material thickness and the engineering requirements of the component surface.
All Brinell hardness testing machines should be regularly checked using certified Brinell Reference blocks and all Brinell microscopes should be regularly checked using a range of certified Reference Indentations, which are available from Foundrax Engineering Products Ltd, and a Foundrax Stage Micrometer.
