Question about a Surface Finish symbol

[popm]

Hi members, can someone explain the meaning of the Surface Finish symbol in the attachment? and what does "C40" mean? Material or Rockwell hardness?

Thanks a lot!

 

[powerhound]

Assuming the print is in inches, the surface finish has to meet a requirement of 200 microinches, which really isn't very smooth at all. As far as the C40 goes, I don't know what it means as it seems to just be stuck in there. Why aren't you asking about note 4? That's a scary one to us.

John Acosta, GDTP S-0731
Engineering Technician
Inventor 2013
Mastercam X6
Smartcam 11.1
SSG, U.S. Army
Taji, Iraq OIF II

 

[popm]

To powerhound, Thank you so much for your answer, looks like it is drawn by a newbie. However, I've seen more weird drawings than this. Have a nice one.

 

[powerhound]

Don't be so sure it's by a newbie. Note #4 is an example of something that people will do for 20 years if they are not actually shown why it's a bad idea. Either that or they get a whole slew of parts that don't work but still meet that requirement.

John Acosta, GDTP S-0731
Engineering Technician
Inventor 2013
Mastercam X6
Smartcam 11.1
SSG, U.S. Army
Taji, Iraq OIF II

 

[CheckerHater]

popm,

If your roughness designation is standard (which is doubtful) “C” could mean circular lay orientation.

Normally numerical value is placed slightly above lay symbol like in enclosed picture. The number indicates sampling (cut-off) length. Unfortunately “40” is outside of standard range.

Another numerical value that is placed below cut-off and somewhere to the right of lay is alternative surface roughness, say Rz if your main roughness was Ra. But Rz is usually clearly identified as such.

If you can communicate with person who created the drawing, don’t be ashamed to ask questions, because the designation definitely isn’t 100% clear.

 

[dgallup]

For the "C40" to be part of the roughness call out, there should be a horizontal line extending from the top right end of the symbol (as in CheckerHater's example). I can't think of any valid explanation of the "C40".

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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.

 

[ctopher]

It's "surface roughness".
I think C40 has something to do with quality of the surface?
Link

Chris
SolidWorks 11
ctopher's home
SolidWorks Legion

 

[jbeckhou]

I believe C40 is the material call out, European = to AISI 1040. 200 finish is only for non-machined areas per notes, which can be done by any production method, per shown roughness symbol.

Petrotrim Services

http://www.petrotrim.com

 

[dgallup]

From the note we know the surface roughness only applies to as cast surfaces. Could C40 designate some kind of casting quality or perhaps a grade of cast iron? This link suggests C40 is similar to AISI 1040.

http://www.makeitfrom.com/material-data/?for=SAE-AISI-1040-S40C-C40-1.0511-G10400-Carbon-Steel

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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.