## Brinell Hardness

If a plain carbon steel test specimen has a Brinell hardness of 10, estimate the tensile strength in MPa.

##
__
__**Hint**

**Hint**

The relationship between hardness and tensile strength is roughly:

$$$TS\:(MPa)\simeq 3.5\:HB$$$

where
$$TS$$
is the tensile strength in MPa, and
$$HB$$
is the Brinell hardness number.

##
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__**Hint 2**

**Hint 2**

Multiply the Brinell hardness number in the problem statement by 3.5.

For plain carbon steels, the relationship between hardness and tensile strength is roughly:

$$$TS\:(MPa)\simeq 3.5\:HB$$$

where
$$TS$$
is the tensile strength in MPa, and
$$HB$$
is the Brinell hardness number.

$$$TS\simeq 3.5(10)MPa\simeq 35\:MPa$$$

Note the units for HB are in psi or kg/mm^2 (Pascals), but the results are usually reported unitless.

$$$\simeq 35\:MPa$$$