Talk:Hardness

Move materials science page back here
This disambiguation page doesn't seem useful - it has over a hundred links to it that are almost entirely referring to the materials science usage. Per WP:MOSDAB: "do not create entries merely because [hardness] is part of the name.... The above does not apply if the subject is commonly referred to simply by [hardness]". People searching for hard water or hard matter are unlikely to use "hardness" alone as a search term - neither of those are referred to simply by "hardness". The difficulty level is linked to at the hard disambiguation page - I believe a hatnote to hard would help anyone who came here looking for the difficulty level.

How do others feel about moving the materials science page back to the main article "hardness"? LyrlTalk C 02:10, 28 July 2007 (UTC)


 * Seems like a good idea. I would merge Hard matter and Hardness (materials science) and put the result at Hardness with a hatnote that points to a merger of the disambiguation pages currently at Hard and Hardness. -- Beland 15:54, 29 July 2007 (UTC)


 * I implemented these merges and moves. -- Beland 17:57, 30 July 2007 (UTC)

Typo
The sentence "The hardest substance known today is aggregated diamond nanorods, with a hardness over 12 of and a stiffness 1.11 of diamond." is clearly malformed, but I have no background in the field, so I don't know how to correct it. PavelCurtis (talk) 18:18, 12 May 2008 (UTC)

Hall-Petch Relationship
"Hardness increases with decreasing particle size. This is known as the Hall-Petch effect. However, below a critical grain-size, hardness decreases with decreasing grain size. This is known as the inverse Hall-Petch effect."

I think the relationship should be stated. The only relation I know that is called the "Hall-Petch" relationship regarding mechanical properties of materials concerns the yeild strength of materials, not the hardness (Where Yield Strength = Intrinsic Strength + k*(grain size)^-(1/2)). I have a feeling you've made an error and that there is no such named relationship for hardness, but this should be sorted out either way.

Cheers.

PeriPeriSalt (talk) 09:44, 7 September 2008 (UTC)


 * According to http://books.google.com/books?id=7EJcg2dWHGAC&pg=PT722&lpg=PT722&dq=hall-petch+hardness&source=web&ots=9qXLJat5dB&sig=MkZ7laYBl-wrGYWXpafe7DXA0Bo&hl=en&sa=X&oi=book_result&resnum=8&ct=result a "Hall-Petch type" relationship is true for hardness. I think the text should reflect that it's a "Hall-Petch type" relationship and not the Hall-Petch relationship. --Wizard191 (talk) 23:53, 7 September 2008 (UTC)

Physics
The physics section in this article is really just an overview of all material science concepts. The whole first half is just a copy of the solid mechanics article. I don't think it really belongs here. I think that the section should be deleted and then the intro about the physics reworked into a sentence format. --Wizard191 (talk) 23:12, 10 September 2008 (UTC)

Hot hardness?
Another article I'm working on (Alloy steel) refers to hot hardness, which is an easy to understand, but isn't noted anywhere. Perhaps it can be added to this article. --Wizard191 (talk) 02:03, 22 September 2008 (UTC)

Shore A & B
I am not an expert but there is no mention of Shore hardness here, which seems to be an omission? Kim53 (talk) 13:01, 14 February 2011 (UTC)


 * That's because it's listed in the indentation hardness article. Wizard191 (talk) 18:44, 14 February 2011 (UTC)

WP:OR removed
I have removed a statement
 * Since the invention of the Mohs scale of mineral hardness, there have been reports of materials harder than the highest mineral on the scale, diamond; so the Mohs scale may be changed in the future.

Per WP:OR - neither it is present in the cited reference nor there is any reliable experimental report of material harder than diamond. Materialscientist (talk) 01:06, 15 March 2011 (UTC)

Problem with scratch hardness section.
It's not actually true that any material will only scratch materials the same hardness and lower. The truth is that a material can't scratch a material that's enough times harder than itself and when a material scratches a material that's only slightly harder, they both scratch each other with the harder material getting scratched less. It's also true that a sharp spike on a material can be scratched more easily than a smooth surface of the same material. i.e. a material can be scratched by a material more times softer than it if it has a sharp spike than if it doesn't. That explains the infamous scratch test where somebody has a real diamond and then they scratch it on glass to see if it's a real diamond or not to see if they're getting cheated on and it gets damaged anyway and the scratch test gives them the wrong answer. It's not only true that the harder a substance is, the more easily it can scratch another substance and the less easily it can be scratched. It's also true that the harder a substance is, the less easily it can scratch itself. Blackbombchu (talk) 02:50, 17 June 2013 (UTC)

External links modified
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Durezza listed at Redirects for discussion
An editor has asked for a discussion to address the redirect Durezza. Please participate in the redirect discussion if you wish to do so. Shhhnotsoloud (talk) 10:02, 20 July 2019 (UTC)

"Orders of magnitude (absolute hardness)" listed at Redirects for discussion
An editor has asked for a discussion to address the redirect Orders of magnitude (absolute hardness). Please participate in the redirect discussion if you wish to do so. Utopes (talk / cont) 20:56, 8 April 2020 (UTC)

Softness
Why has softness been redirected to Hardness when this article does not deal with softness? Some fibres, eg modal, are softer than cotton. An article about softness would cover things like how this 'softness' is defined, what units of measure are used, and how this is measured. The redirection should be undone and a stub for softness be created I think. FreeFlow99 (talk) 15:01, 11 April 2020 (UTC)
 * It is the same thing. -Roxy, the PROD. . wooF 12:20, 15 April 2020 (UTC)

"Newton-square second per metre" listed at Redirects for discussion
An editor has asked for a discussion to address the redirect Newton-square second per metre. Please participate in the redirect discussion if you wish to do so. signed,Rosguill talk 18:27, 13 April 2020 (UTC)