Contact US

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!

*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

Indication of geometric tolerances on drawings

Indication of geometric tolerances on drawings

Indication of geometric tolerances on drawings

Hi everyone.

I work on design of valves for oil&gas and currently on our drawings we only indicate the general tolerances with the indication "ISO 2768-mK". We don’t indicate any specific geometric tolerances on individual dimensions/geometries.
After carrying out a functional analysis on our components, we have identified a series of specific geometric tolerances that we would like to implement on the singular parts drawings.
Before implementing geometric tolerances massively on all drawings, my team was thinking about the possibility of creating a “master document” for each type of component (e.g. body, flange, bonnet, etc.), where indicate (in a generical way) the geometric tolerances to be applied with the respective deviations, tabulated by dimensional ranges. In this case we would have the single drawings without any indications of specific geometric tolerances, which would be covered by the master document.

Personally I think that this solution, even it would lighten the drawings a lot, is not correct for a number of reasons, including:
- would it be in accordance with GD&T standars?
- the quality system should uniquely link a particular design to the master document
- the supplier who machines our components should have the master document in hand in addition to the drawing, which is impractical and could create interpretative errors since the individual drawings are not identical to those indicated on the master document.

It being understood that in my opinion the correct solution would be to indicate all the geometric tolerances directly on all the drawings, I kindly wanted to know your opinion, and if the above solution is not applicable, I would like to know where it is specified on the GD&T standards ...

Thanks for your help!

RE: Indication of geometric tolerances on drawings

The more links in the chain of information, the more likely something is to break.

Having a standard for tolerancing parts makes sense. Forcing the people who make the parts interpret the standard for every part is asking for trouble. Use the standard as a guide for putting explicit tolerances on the part drawings.

RE: Indication of geometric tolerances on drawings

I'm not familiar with "ISO 2768-mK". But, a simple note on the dwg indicating you are following this spec, and indicate standard GD&T on the dimensions are all you need. Also, training for all involved who needs to understand it.
Having a master document that spells out more than this only adds confusion and more work.

ctopher, CSWP
SolidWorks '17
ctophers home
SolidWorks Legion

RE: Indication of geometric tolerances on drawings


The standard tells everybody what the symbols and specifications on your drawing mean. It is a complete waste of time if you do not apply the symbols and specifications.


RE: Indication of geometric tolerances on drawings

Thanks for your answers!

RE: Indication of geometric tolerances on drawings

Hi, Angel25:

You need to think about definition of your components. You don't want to send multiple documents to potentially confuse your vendors.

If you order a part named "ABC", you should send a drawing that shows definition of this part "ABC". You should not send any other documents that are not referenced on the drawing you sent.

"the supplier who machines our components should have the master document in hand in addition to the drawing" sounds scary. Is your part defined by "its drawing" or by "the master document"? Your part needs to be defined by one document ONLY. You can have additional documents, but they will need to be referenced in your drawing.

Best regards,


RE: Indication of geometric tolerances on drawings

Hello jassco,

I agree with what you say. Also for us each component is uniquely defined by its drawing, so from what we have said, a single master drawing could not be applied to the drawings.

Thank you

RE: Indication of geometric tolerances on drawings

Hi, Angel25:

You can still send the single master drawing to your vendor in addition to your component drawing as long as the component drawing calls out this single master drawing. However, you should not duplicated anything in your single master drawing that already exist in the component drawing.

If I were your vendor, I would look at your PO to determine what you order. If you would send me the single master drawing that is not referenced in your component drawing, I would not even look at it.

Best regards,


RE: Indication of geometric tolerances on drawings

Hi Alex,

I understand, thanks for your feedback.

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! Already a Member? Login


Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close