The following discussion is an archived debate of the proposed deletion of the article below. Please do not modify it. Subsequent comments should be made on the appropriate discussion page (such as the article's talk page or in a deletion review). No further edits should be made to this page.
Seems to be a WP:SYNTH violation. The other two scales being compared to Mohs are not notable on their own, as their articles are both redlinks and the sources are just publications by people the scales are named after. Deprodded because "the scales might be notable". Ten Pound Hammer • (What did I screw up now?)02:20, 18 April 2022 (UTC)[reply]
Comment. Not my area but I'm unsure that the other two scales are unnotable; there's a lot of publications on different ways of measuring hardness; the first one I clicked on was a 1974 Scientific American review[1] that discusses the Wooddell scale, which it calls the Moh–Wooddell scale, for several meaty paragraphs with a table. I don't see why this falls under WP:Synth. At very least, as I suggested when I removed the prod, it should be merged into the relevant section in the article on hardness. Espresso Addict (talk) 09:32, 18 April 2022 (UTC)[reply]
It's suggesting a connection between the Mohs scale and two other scales that aren't notable on their own, using only publications by the creators of those two scales. Why those two scales and not some other ones? What part of this even suggests there's a link? Ten Pound Hammer • (What did I screw up now?)14:20, 18 April 2022 (UTC)[reply]
Purely off the top of my head: the Mohs scale is a method of determining hardness by scratching one material with another, invented c.1820. A child can use it but it has numerous problems for scientific use, in particular it is skewed so that nearly every material of interest is right at the top end. According to the Sci Am review I linked, which you can read as well as I can, the Wooddell scale is a 1935 attempt to fix this problem, by scaling the Mohs values. I assume the other scale mentioned is another such attempt. Other methods of measuring hardness don't use scratching but rather pressing or something else. This is also explained in the review.
Are the other two scales notable? Probably not. To make an article comparing three things, when two of those three don't have articles, is putting the cart before the horse at best. Ten Pound Hammer • (What did I screw up now?)02:41, 19 April 2022 (UTC)[reply]
Try correcting the spelling? Or searching in more specialised places? Something published in 1935 might not be all that well reviewed on the internet.
As to the more general point, the article is correctly discussing three similar entities, two of which might not need their own articles. I'm genuinely baffled as to the problem here. Espresso Addict (talk) 02:56, 19 April 2022 (UTC)[reply]
Historically, at worst, Ridgway and Wooddell extended Mohs to specific synthetic materials industries, while Mohs was a field mineralogist.
"Scratch hardness" is certainly a notable thing, having encountered it many times in multiple youth education systems.
I get it that Ridgway's and Wooddell's papers are primary, but they clearly exist as practical improvements to Mohs to make the material hardness measurement method more functional for industry. A relatively likely situation here is that the OP is familiar with hardness scales in some fields where either Ridgway or Woodall scales are known, so, I hackle at the "random" appellation that strikes me personally as presumptively NPOV. "Random" is speculative. Mohs is "arbitrary" by definition.
I suggest searching on the titles "Hardness Values for Electrochemical Products" and "Method of Comparing the Hardness of Electric Furnace Products and Natural Abrasives", which turns up more books and papers citing Ridgway, et al, 1933, or Wooddell 1935 than I have time to assess.
C. Barry Carter, M. Grant Norton (2013). Ceramic Materials: Science and Engineering. [citing Ridgway, et al, 1933] Note that in Chapter 16 we consider the extended [industrial] version as defined by Ridgway but it is not nearly so widely used in the Gem industry.(ironically published the same year as the WP page)
Industrial Minerals and Rocks: (nonmetallics Other Than Fuels). American Institute of Mining, Metallurgical, and Petroleum Engineers. 1960. Mineralogical hardness or "scratch" hardness is as expressed in Mohs scales is an important property in evaluating abrasive materials, but it is only one of several essential properties ... both "scratch" hardness and toughness must be considered. ... The Mohs scale is inadequate both because the methods of testing are very crude and because the intervals between steps in the scale are not uniform. ... Numerous attempts have been made to remedy these deficiencies. Ridgway, Ballard, and Baily [1933] proposed an extension of Mohs scale to include artificially prepared substances.
R. W. Rice, A. G. Evans (1978). "Hardness and Its Relation to Machining". NBS Special Publication, (562): 185–187. Since translational motion is involved in machining operations, it would appear that scratch hardness is a more relevant parameter than the commonly used indentation hardness. ... Also in some earlier studies the rate of lapping was used as an extension of, or replacement for, the familiar Moh [sic] hardness scale.[14 (Wooddell 1935)]((cite journal)): CS1 maint: extra punctuation (link)
Several current ceramic coating manufacturers name "Mohs, Ridgway, and Wooddell" as a triad, but I will not try to see whether they were influenced by WP.
Kevin J. Anderson. "Hardness Testing"(PDF). MRS Bulletin. Historical Note (November 1994): 7. Retrieved 2022-04-21. For all its usefulness, the Mohs scale is arbitrary and nonlinear. ... When synthetic abrasive materials become widely available at the beginning of this century, R.R. Ridgway and his co- workers, finding they needed more numbers at the high end of the scale, modified Mohs' scheme. C.E. Wooddell measured how much various minerals resisted wearing down with diamond abrasives, which allowed a finer categorization between the Mohs numbers of 9 and 10. Ridgway arbitrarily shifted the value of diamond to 15 on the scale instead of 10, which allowed them to assign hardness numbers of 12 to fused alumina, 13 to silicon carbide, and 14 to boron carbide.
Francis P. Bundy (1974). "Superhard Materials". Scientific American. 231 (2): 62–71. Retrieved 2022-04-21. Wooddell indexed his scale by assigning quartz and corundum their Mohs values of 7 and 9, and the scale is therefore called the Mohs-Wooddell scale.
Don't Delete (not the same as "Keep") based on the notability of Ridgway and Wooddell relative to Mohs, they are the extension of Mohs into 20th Century science.
Don't Split Ridgway and Wooddell are inseparable topics, but might not have made it into the 21st Century.
Redirect Ridgway hardness scale (syntheic ceramics) and Wooddell hardness scale to wherever this content ends up residing.
Keep or Merge with Mohs scale of mineral hardness'? That is a follow-on topic IMO: Is "scratch hardness" a broad topic (cf indent hardness) or inseparable from Mohs scale, et al?
@TenPoundHammer, there is nothing wrong with nominating a scruffy stub article for deletion. But this topic goes well beyond the current content of the article. We don't have good coverage of engineering topics because there are few editors in this area, so nominators of engineering articles for deletion aren't expected to be experts. StarryGrandma (talk) 01:17, 22 April 2022 (UTC)[reply]
First, this is a delete discussion, but it has ranged into development of the topic.
But, the page presently is missing clear definitions of scratch hardness (especially as compared to the other types of hardness) and scratch test (broad and narrow definitions).
I have just skimmed Ridgway 1933, and it has an interesting history of the topic. (link when I get out of bed tomorrow)
2.) If it's not about alternate scales, why does that take up more of the article ...
A) It is a stub. B) From Ridgway 1933, we see there are multiple scratch test methods.
A clear keep since the subject is beyond any doubt notable, widely written-about, widely used. Further, there is nothing SYNTH about tabulating the hardness of a set of materials by three different measures. That is merely collating verifiable information to give a reader an overview of what the scales do. Elemimele (talk) 06:07, 25 April 2022 (UTC)[reply]
We don't have good coverage of all topics, not just engineering. People recognize poor coverage in their own fields, but it's actually poor coverage in all fields.
This wasn't the easiest to search for sources for, since sometimes I actually have the books on my bookshelf, but the very first Google Books result for me was ISBN9780080942452 where a professor of mechanical engineering devotes the whole of §6.6 to scratch hardness. Two sources, you say? Easy as pie! The third result of the same search was David Tabor's 1951 book The Hardness of Metals, which has good introductory level material on scratch hardness in, unsurprisingly, its introduction on pages 1 to 3.
Atkins tells us that there's a whole distinct second measurement of scratch hardness that isn't Mohs's. It's Thomas Turner's sclerometer. Add in that name and '"Hardness of Metals", Trans. Birm. Phil. Soc. 1886' and entire bibliographies on scratch hardness start turning up, and then a 1934 book by Hugh O'Neill on The Hardness of Metals and its Measurement that brings in Adolf Martens's quantification of Turner, as mentioned, and indeed as cited by, Atkins. None of those are in the article at hand. So yes, this is clearly a poor stub with plenty of scope for expansion.
Keep, a clearly notable topic that has had applications in gemology for hundreds of years.[1] Many reliable sources are available to improve the article.[2][3][4][5][6]
The above discussion is preserved as an archive of the debate. Please do not modify it. Subsequent comments should be made on the appropriate discussion page (such as the article's talk page or in a deletion review). No further edits should be made to this page.