×
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

Limit Tolerance Text Placement
2

Limit Tolerance Text Placement

Limit Tolerance Text Placement

(OP)
Howdy All,

I have a question about how Limit Tolerance type dimensions should be written. I have some old drawings with diameter dimensions to the Inside of a machined surface and diameter dimensions to the Outside of machined surfaces.

-When displaying a dimension for the inside diameter of a surface the smaller number is on top. Example 9.995/10.005
-When displaying a dimension for the outside diameter of a surface the larger number is on top. Example 10.005/9.995

The purpose seems to be:
1) When a machinist is machining an inside surface the first number he will machine too is the smaller number – so the smaller number is on top or first.
2) When a machinist is machining an outside surface the first number he will machine too is the larger number – so the larger is on top or first.

I've always put the larger number on top regardless of Inside or Outside machining, but can't explain way smile .

My question is – Is this practice part of any current (or past) written "standard" that can be quoted from? ANSI, ASME, ISO, Global anything?

If not - Is there something in any of the Drafting Standards that defines the placement of the smaller and larger numbers when using Limit Tolerance type dimensioning?

Thanks

Tobin Sparks
www.nov.com

RE: Limit Tolerance Text Placement

ASME Y14.5M-1994 section 2.2 (& figure 2-1)addresses this.  High limit is placed above the low limit.

Not sure about historical use though.

KENAT,

Have you reminded yourself of FAQ731-376: Eng-Tips.com Forum Policies recently?

RE: Limit Tolerance Text Placement

Back in the day of hand drawings & each company having it's own drawing standards, I worked for a British company that followed that practice.  I don't think it is part of any current (inter)national standard.

ISO 406:1987 section 5 says:
The upper deviation or the upper limit of size shall be written in the upper position and the lower deviation or the lower limit of size in the lower position, irrespective of whether a hole or a shaft is toleranced.

RE: Limit Tolerance Text Placement

(OP)
KENAT and dgallup

Thank you for your responses. Both ASME and ISO agree and now I know why I have been putting the larger number on top all along smile .

Thanks Again

Tobin Sparks
www.nov.com

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