Brinell to Rockwell hardness conversion
Brinell to Rockwell hardness conversion
(OP)
Hi all. I've exhausted all the Google searches I can think of and didn't find any threads related to this, so here I am, with a question; Is there a way to convert a HBW (Brinell) of 50 on the 2.5/62.5 scale to a measurement on the 10/3000 scale? Ultimately I'm trying to cross this to a Rockwell hardness but cannot find any tables that use the 2.5/62.5 scale. Tables? Formulae? Mystical ball of answers?
Thanks for any help or direction.
Jason
Thanks for any help or direction.
Jason





RE: Brinell to Rockwell hardness conversion
RE: Brinell to Rockwell hardness conversion
RE: Brinell to Rockwell hardness conversion
ione, I agree. My goal isn't to necessarily find an equivalent on the 10/3000 (29420 N) scale, but rather to find a Rockwell hardness cross. So far, all my searching has yielded no tables or conversions that include a Brinell hardness as low as 50.
RE: Brinell to Rockwell hardness conversion
Most of the published data is for steel, and you will probably not find Brinell hardnesses as low as 50 for steel. Certainly when I was collecting data for inclusion in my unit conversion program Uconeer I did not find any values as low as 50. If you Googled hardness conversions I am sure you will have seen Uconeer, but it has a lower limit of 52.9 on the Brinell scale.
Perhaps you will have better success if you approach suppliers of the material that you are measuring the hardness of. Or approach the hardness tester manufacturers.
Katmar Software
Engineering & Risk Analysis Software
http://katmarsoftware.com
RE: Brinell to Rockwell hardness conversion
If this Brinell measurement was achieved on an aluminum alloy, then you can use ASTM E 140 or ISO 18265 to convert it to an approximate Rockwell number. 50 HB is equivalent to 56 HV, 59 HRE (1/8" ball, 100 kgf), or 64 HR15T (1/16" ball, 15kgf). This is extremely soft, and therefore does not register a valid reading on the HRB scale (1/16" ball, 100 kgf). The sample would need to be substantially harder in order to achieve a valid HRB reading, e.g. 70 HB is ~ 80 HV, 28 HRB, 80 HRE, or 74 HR15T.
You can obtain ASTM E 140 and ISO 18265 directly from their respective publishers, or from a licensed reseller such as Global Engineering Documents:
http://www.astm.org
http://www.iso.ch
http://global.ihs.com
RE: Brinell to Rockwell hardness conversion
The application of a different load and a different diameter indenter (keeping the same indenter material) on a sample should be to get a different indentation diameter.
HBN = 0.102*2F/(PI*D*SQRT(D^2-d^2))
Now as it is known a correlation exists between Brinell hardness number and ultimate tensile strength (UTS), taking the UTS as a constant value the HBN should be unambiguous and not dependent on the scale used to perform the test. So, allowed from a theoretical point of view, one could perform the test with different Brinell scales on the same sample, the Brinell number should be the same.
RE: Brinell to Rockwell hardness conversion