×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Conversion of Ra to Rz surface roughness

Conversion of Ra to Rz surface roughness

Conversion of Ra to Rz surface roughness

(OP)
Hi,
Is there any thumb rule or acceptable guidelines to convert Ra surface roughness values to Rz surface roughness values?

RE: Conversion of Ra to Rz surface roughness

There is no formal or accurate conversion as they are measuring two different characteristics. However, as a rule of thumb, I've seen factors of 8 to 10 used (multiply Ra by 8 or 10 to get Rz).

----------------------------------------

The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.

RE: Conversion of Ra to Rz surface roughness

You need to get the standard out and read the definitions. I have seen the ratio between them as low as 5 and as high as 20. They are two very different characteristics.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

RE: Conversion of Ra to Rz surface roughness

Hello,

what I propose (& do it myself all the time) is to look at this from the manufacturing, i.e. specific machine and machining p.o.v.
In the / some appropriate handbook there shall / should be tables alike this one:

which makes it possible to converse roughness values, at least for standard purposes (~ I'm located in heavy to medium mechanical manufacturing).
Additional hint: for every machining process the usual equipment is characterized by a certain achievable surface quality range. The range itself is defined by e.g. speed of machining, quality of tools,..
Ultimately, your request is a good incentive to talk to (your) workshop people winky smile
Regards

Roland Heilmann
Lpz FRG

RE: Conversion of Ra to Rz surface roughness

(OP)
Hi All,
Thanks for the reply. It was helpful.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources