# Talk:Surface roughness

## Untitled

surface finish shown in s for e.g. 2.0s

## Surface finish tolerances chart is INCORRECT

The units on "Surface Finish Tolerances In Manfacturing.png" are swapped--e.g. 8 microinches corresponds to .2 microns, not the other way around. I've notified the image's creator. Sandheep (talk) 18:06, 21 April 2008 (UTC)

You are right about the image. It is easiest if Emok does the change (because he had the tools to create it in the first place), so I just let him know. His last contribution was on April 5th, so if he doesn't react soon I will make the change myself.
By the way, you don't need to YELL that the image is "INCORRECT". ;-)
Federico Grigio, alias Nahraana (talk) 10:34, 22 April 2008 (UTC)
Oops, sorry for the mistake. Thanks for catching it. I can't edit the file right now, but I'll correct it and repost soon. Emok (talk) 01:02, 23 April 2008 (UTC)
Sorry for the yelling--just trying to call attention to the error--Thanks for fixing, Emok Sandheep (talk) 03:35, 29 April 2008 (UTC)

(this was removed august 2007) --Berland 06:23, 9 September 2007 (UTC)

## Surface Finish Index Numbers

Does anybody have any detailed information on the Surface Finish Index numbers, i.e. A1, A2, C1, C2, etc? This would be useful to record here... FusionKnight 14:27, 18 October 2007 (UTC)

## Merging rugosity into roughness

The following discussion is closed. Please do not modify it. Subsequent comments should be made in a new section.

The result was not merge RUGOSITY into ROUGHNESS. The merge was proposed one year ago and all opinions expressed are against it. -- Federico Grigio, alias Nahraana (talk) 17:54, 25 April 2008 (UTC)

I am not an expert on the subject, but from looking at both articles it looks like rugosity is used more for natural sciences and roughness for engineering. If this is true, having the articles divided (with a "see also" link to each other) seems natural and so I would suggest not to merge them. Nahraana (talk) 19:47, 2 February 2008 (UTC)

On the other hand, Wikipedia:Content forking suggests that "Articles should not be split into multiple articles so each can advocate a different stance on the subject". So, if the two terms are synonimous, maybe we should merge the articles. Opinions anyone?
Are they synonimous? The Free Dictionary gives different definitions for rugosity and roughness, and the only difference between them seems to be that rugose is used for botany specifically. Since I am not a native speaker, can anyone say if there is a real perceived difference between "rugosity" and "roughness" in the English language? Federico Grigio, alias Nahraana (talk) 22:49, 13 February 2008 (UTC)
These two articles should not be merged because they are not synonymous. In an abstract sense they may be related, but they have different meanings when used technically. In mechanical engineering, metrology, manufacturing, tribology, etc. roughness has a precise definition that is explicitly defined in various standards published by ISO and ASME. These standards never mention the term rugosity. Emok (talk) 00:21, 29 March 2008 (UTC)
So what does rugosity mean when used technically? Federico Grigio, alias Nahraana (talk) 20:30, 29 March 2008 (UTC)
From googling, it seems that rugosity is used in chemical engineering and marine sciences. I don't know much about it beyond that. My point is just that the standards have algorithms for separating out the high-frequency component of surface texture, and they call the result roughness, never rugosity. Emok (talk) 18:10, 30 March 2008 (UTC)
OK. So, in the light of Emok's comments, I confirm my opinion that the articles should be left divided, with a "See also" link to each other. Federico Grigio, alias Nahraana (talk) 10:00, 1 April 2008 (UTC)

The above discussion is closed. Please do not modify it. Subsequent comments should be made in a new section.

## Are the symbols correct?

The symbols for surface finish specification show the symbols for removal and no removal. Is this correct? I do not have a copy of ASME Y14, but I do have BS EN ISO 1302:2002 to hand. Figure 4 (para 4.4) shows the symbols the other way around: the "tick" with a circle meaning "material shall not be removed" and the "tick" with the horizontal line meaning "material shall be removed".

If the illustration is correct, can the paragraph be updated to state that BS EN ISO 1302:2002 have the opposite definitions, as it is implied in the text that the definition is the same for both. StephenBuxton (talk) 16:20, 31 March 2008 (UTC)

Sorry, that was a mistake. It should be corrected now. Thanks for pointing it out. Emok (talk) 19:11, 31 March 2008 (UTC)
No worries. StephenBuxton (talk) 06:52, 1 April 2008 (UTC)

## Basic Definition suggestion

It seems to me that it would be useful in the basic definition to include one or two samples of roughness measurements in the most commonly used scale which is RSubscript texta. I have limited familiarity with that scale but if I did not I might be confused about whether a high rating or a low rating is smoother. I would do the edit myself but I do not feel technically competent to insure that I would get it completely correct. I would suggest the following sentence be added to the basic definition "The lower the Ra or RMS, the smoother the finish." Drucker0905 —Preceding unsigned comment added by Drucker0905 (talkcontribs) 13:16, 6 November 2008 (UTC)

## Tolerancing?

I came to this page for references on tolerancing symbols. Geometric dimensioning and tolerancing mentions flatness but not roughness. What can y'all say about this? For exmaple, if I see "SURFACE ROUGHNESS ${\displaystyle \diagdown \!\!\!^{1.6}\!\!\!\diagup }$ OR BETTER", what does that mean? —Ben FrantzDale (talk) 14:29, 9 February 2011 (UTC)

I believe the article you actually want is Surface finish; specifically section Specification. It means that the surface roughness must be no worse than 1.6 μm. Wizard191 (talk) 15:39, 9 February 2011 (UTC)
Thanks. I added a few links so the next person in my shoes finds it. —Ben FrantzDale (talk) 18:44, 9 February 2011 (UTC)
sir I have not copied the subject surface roughness. I have referred the book by Farazdak Haidary.Jayeshmore77 (talk) 17:26, 5 October 2011 (UTC)

## The Older "S" Measurement

I think there was an older way of expressing Rmax, which was "S". In other words, 1.6S = 1.6 Rmax (microns). I think this "S" notation can still be found in a number of technical materials. I think it would be helpful for the article to include some reference to this older "S" notation. --Westwind273 (talk) 16:17, 6 October 2011 (UTC)

OK sir, I will leave an edit summary onwards. Sorry I was unknown of it, yet.Jayeshmore77 (talk) 12:49, 8 October 2011 (UTC)

## Rmax

I cannot seem to find anything about Rmax / Ry / Rma (http://www.watsontooling.com.au/pdf/175-176.pdf). Where should this be in the box? It is not the same as Rt. Best regards Kenneth from Sweden. 192.138.116.230 (talk) 14:18, 23 November 2012 (UTC)

I agree that this seems to be poorly explained. Roughness is important in sealing. For a good explanation of the various R values, see pages 5-3 and 5-4 of the Parker O-ring handbook at http://www.parker.com/literature/ORD%205700%20Parker_O-Ring_Handbook.pdf Perhaps this type of explanation could be incorporated into the article. --Westwind273 (talk) 22:42, 23 June 2014 (UTC)

## Detrimental?

The article states that roughness is always considered detrimental in engineering. This is not correct. There are a number of instances where increased roughness is desirable and beneficial. For example, higher roughness on an elastomer surface can reduce stiction and allow the elastomer surface to separate more easily from another contacting solid. --Westwind273 (talk) 19:05, 22 May 2014 (UTC)

## Profile Roughness Parameters Image

The image used in this section to help understand the roughness parameters appears to be in Russian. Could this be translated for the English Wiki? It also appears that few of the parameters are referenced in the text, is this actually a useful image to have then? 40.140.132.20 (talk) 11:44, 4 August 2016 (UTC)

## Translation of image

I agree with 40.140.132.20. The image must be translated for the English Wiki! And is necessary that roughness parameters be adapted according to standard ISO 4287:1997, "Geometrical product specifications (GPS)-Surface texture: Profile method -Terms, definitions and surface texture parameters". Dorimedont (talk) 06:17, 16 May 2017 (UTC) from Romania