Confusion about Brinnell scale

[Jim]

I just came from the periodic charts. As per this source, lead has a Brinnell hardness of 38.3. Seems like I heard that lead has a BHN of 5 or some such.
Can somebody straighten me out on this?

[OeldeWolf]

There are several different hardness scales. The Brinnel hardness scale puts pure lead at 5, you are correct. Check the chart, perhaps they are using the rockwell scale.

[Jim]

It specifically says Brinnell. Wikipedia also lists the hardness of lead at this same value. I don't have a clue.

[Whitespider]

Jim,

Wikipedia lists lead as Brinell Hardness = 38.3 MPa.

(MPa) means a “Pascal Unit” not the Brinell Hardness Number (BHN).

I’m not sure how a (BHN) is converted to (MPa). I do know that (MPa) is a (SI) value use in the “International System of Units” (Système International d'unités) or (SI). :veryconfu In other words, the (MPa/SI) value is used universally throughout world and (BHN) isn’t. I suspect that the publications you’re looking at are also expressed in the (SI) value rather than the (BHN).

Remember when we were supposed to convert to the “Metric System”? :roll:

[John Boy]

1(MPa) = 0.18BHN
38.3 x 0.18= 6.894Bhn

[scrapcan]

John Boy

Nice reply, Do you have a reference to where you found that? Just for the curious you know.