×
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

co-axial features

co-axial features

co-axial features

(OP)
Re: Fig. 4-24 in ASME Y14.5-2009, and Fig. 4-19 in ASME Y14.5M-1994. Did they put positional tolerancing without a datum back in the standard when I wasn't looking?

RE: co-axial features

You mean on the right-hand side of the drawing...
If two coaxial features are the same size and called out together, then it's legal to use the position symbol without a datum. In a sense, each end of the part creates a datum for the other, ensuring coaxial alignment.

I think this has always been OK, but it's a special case of two or more features that are the same size and are to be coaxial.

John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems

RE: co-axial features

Position may be used on coaxial diameters without a datum reference, this is revised in 2009 standard, please ref to 7.6.2.3 and Fig.7-59 for details.

Season

RE: co-axial features

2 coaxial feaures of size don't have to be same size.. you still can use a Position control with no datum. Only difference is that you would call the sizes DIA separately.

RE: co-axial features

Good point, Tarator. That's specifically mentioned in paragraph 7.6.2.3 of the Y14.5 standard (and shown in Fig. 7-51).

John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems

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