Regarding the issue of surface roughness, how is the conversion between RMS and RA done?
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The customer’s quotation specifies that the tubes must be bright annealed and electropolished to 30RMS. I contacted several domestic companies, and they all use an surface roughness value of RA. Thank you first!
Root Mean Square roughness – the author can read this article for more information: Determining the roughness of ultra-smooth optical surfaces: http://www.haiheng17.com/haiheng17_Article_15164.html. Basic knowledge on surface roughness: http://news.weeqoo.com/2007/9/20071018154836232415.html. This post was last edited by guanshian on 2008-9-29 at 11:34
My understanding: RMS is the root mean square, and RA is the arithmetic mean； But for this specific order, how should we set requirements for the company that provides polishing services? Because it seems they can only understand RA; they have never used RMS and don’t know how to convert it.
RMS denotes the root mean square value of surface roughness, with the unit in nm. Ra represents the arithmetic average, with the unit in micrometers. The conversion formula is Ra x 40 = RMS
I suggest you pay attention to the units, as the RMS system uses imperial units. Generally, the calculation is: RMS*25.4/1000=RA. For example, RMS64 = 64*25.4/1000= RA 1.6. Some commonly used values are as follows: RMS250 = RA6.4, RMS125 = RA3.2, RMS64 = RA1.6, RMS32 = RA0.8
The answer on the fourth floor was excellent; our company often encounters this standard when undertaking tasks related to polishing the inner surfaces of pipes.
5# airgun001
The formula is as follows: RMS*25.4/1000=RA; 5th floor is the correct answer