The Cove Business Standards Discussion Forums More Free Files Forum Discussion Thread Post Attachments Listing Cove Discussion Forums Main Page
UL - Underwriters Laboratories - Health Sciences
Go Back   The Elsmar Cove Business Systems and Standards Discussion Forums > Common Quality Assurance Processes and Tools > Inspection, Prints (Drawings), Testing, Sampling and Related Topics
Forum Username

Elsmar Cove Forum Visitor Notice(s)

Wooden Line

Surface Roughness - What is difference between Ra, Rmax & Rt


Elsmar XML RSS Feed
Elsmar Cove Forum RSS Feed

Monitor the Elsmar Forum
Sponsor Links




Courtesy Quick Links


Links that Cove visitors will find useful in your quest for knowledge:

International Standards Bodies - World Wide Standards Bodies

ASQ - American Society for Quality

International Standards Organization - ISO Standards and Information

Howard's
International Quality Services


Marcelo Antunes'
SQR Consulting, and
Medical Devices Expert Forum


Bob Doering
Bob Doering's Blogs and,
Correct SPC - Precision Machining


Ajit Basrur
Claritas Consulting, LLC


NIST's Engineering Statistics Handbook

IRCA - International Register of Certified Auditors

SAE - Society of Automotive Engineers

Quality Digest

IEST - Institute of Environmental Sciences and Technology

Reply
 
Thread Tools Search this Thread Rating: Thread Rating: 2 votes, 5.00 average. Display Modes
  Post Number #1  
Old 25th July 2007, 04:48 AM
reddy

 
 
Total Posts: 1
Question Surface Roughness - What is difference between Ra, Rmax & Rt

Can anybody help me in differentiating surface roughness measurment values in Ra,Rmax and Rt. In what conditions we use Rmax.

Sponsored Links
  Post Number #2  
Old 25th July 2007, 06:33 AM
Ted Schmitt's Avatar
Ted Schmitt

 
 
Total Posts: 668
Re: Surface Roughness - What is difference between Ra, Rmax & Rt

Quote:
In Reply to Parent Post by reddy View Post

Can anybody help me in differentiating surface roughness measurment values in Ra,Rmax and Rt. In what conditions we use Rmax.
Welcome to the Cove !

Average roughness (Ra). The average height of the bumps on a surface, measured in micrometres or microinches.

Rt = is the difference between the highest peak and the lowest valley

Rmax = is the highest peak
Thank You to Ted Schmitt for your informative Post and/or Attachment!
Sponsored Links

  Post Number #3  
Old 25th July 2007, 07:57 AM
Stijloor's Avatar
Stijloor

 
 
Total Posts: 15,122
Re: Surface Roughness - What is difference between Ra, Rmax & Rt

Quote:
In Reply to Parent Post by reddy View Post

Can anybody help me in differentiating surface roughness measurment values in Ra,Rmax and Rt. In what conditions we use Rmax.
Hello reddy,

Here is some info.

http://www.mfg.mtu.edu/cyberman/qual...ace.html#para2

Hope this helps.

Stijloor.
  Post Number #4  
Old 25th July 2007, 08:22 AM
AndyN's Avatar
AndyN

 
 
Total Posts: 8,459
Question Re: Surface Roughness - What is difference between Ra, Rmax & Rt

Surface finish is often called out for two reasons:-

Functional performance, such as in a sealing ring application, bearing surfaces;

Appearance, where the finish has to look or feel smooth, etc. or requires further processing

It would be helpful to know how your organization is applying Ra to it's products.
  Post Number #5  
Old 25th July 2007, 10:38 AM
tenaiwa

 
 
Total Posts: 20
Re: Surface Roughness - What is difference between Ra, Rmax & Rt

Hello,
It depends on your application
Pls consider also
function surface vs No function
friction->rolling or sliding
clearance fit or press fit
dimension presion of product
stress/load exist or not (corner,concave angle..)

hope it helps a little.
  Post Number #6  
Old 25th July 2007, 10:58 AM
harry

 
 
Total Posts: 6,274
Re: Surface Roughness - What is difference between Ra, Rmax & Rt

Also have a look at here, here and here.

Last edited by harry; 25th July 2007 at 07:47 PM. Reason: fix link
  Post Number #7  
Old 25th July 2007, 11:51 AM
Stijloor's Avatar
Stijloor

 
 
Total Posts: 15,122
Re: Surface Roughness - What is difference between Ra, Rmax & Rt

Quote:
In Reply to Parent Post by harry View Post

Also have a look at these threads.

Hello Harry,

Somehow, the link did not work.

Stijloor.
Thanks to Stijloor for your informative Post and/or Attachment!
Reply

Lower Navigation Bar
Go Back   The Elsmar Cove Business Systems and Standards Discussion Forums > Common Quality Assurance Processes and Tools > Inspection, Prints (Drawings), Testing, Sampling and Related Topics

Bookmarks



Visitors Currently Viewing this Thread: 1 (0 Registered Visitors (Members) and 1 Unregistered Guest Visitors)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Forum Search
Display Modes Rate Thread Content
Rate Thread Content:

Forum Posting Settings
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Similar Discussion Threads
Discussion Thread Title Thread Starter Forum Replies Last Post or Poll Vote
When a Part Print specifies 10 Rmax on a Surface - Rmax Settings & Standards? realsteeltools General Measurement Device and Calibration Topics 2 21st October 2013 02:30 PM
Correct Length to Measure Surface Roughness Spacewalker Inspection, Prints (Drawings), Testing, Sampling and Related Topics 4 7th January 2010 04:08 PM
The difference between Rz and Rz3 Surface Roughness Italian1022 Inspection, Prints (Drawings), Testing, Sampling and Related Topics 6 27th August 2009 08:05 AM
Surface Roughness Testing - Comparison of models for measuring Ra, Rmax, Rt, Rz schnuer Inspection, Prints (Drawings), Testing, Sampling and Related Topics 4 8th April 2008 05:39 PM
Honda Surface Roughness Callout (ex. 12.5S) ksanders Customer and Company Specific Requirements 5 3rd June 2004 09:57 PM



The time now is 05:16 PM. All times are GMT -4.
Your time zone can be changed in your UserCP --> Options.


 
 


NOTE: This forum uses "Cookies" - A Peachfarm Internet Property