×
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

How much would be differenct between these two types of tolerating ?

How much would be differenct between these two types of tolerating ?

How much would be differenct between these two types of tolerating ?

(OP)
Hi All

for a cylinder that is supposed to be inserted into another container(cylindrical) how much is it different if I put for its external diameter : 78 h7 (-0.03 ,0 ) or if I dimension it : 78 (-0.4 , -0.02) ?

RE: How much would be differenct between these two types of tolerating ?

LCform,

Take a look at the ANSI limits and fits in your Machinery's Handbook. These are based on ISO tolerances. They classify and explain a huge series of fits.

--
JHG

RE: How much would be differenct between these two types of tolerating ?

You forgot to tell us what tolerances you have on your "other cylinder"

"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future

RE: How much would be differenct between these two types of tolerating ?

Unless I'm missing something, here is the difference...
Using your first method, the limits of size would be 77.97 - 78.00
Using your second method, the limits of size would be 77.60 - 77.98

Seems like a pretty significant difference.

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

RE: How much would be differenct between these two types of tolerating ?

(OP)
CORRECTION :

I apologize , the second tolerance was 78 (-0.04 , -0.02), I know the ANSI limits and fits like h7 and so , but sometimes the tolerances are chosen like arbitrary ? that I don't find it in the handbooks , that's why I asked

RE: How much would be differenct between these two types of tolerating ?

Your tolerance is only half of the problem.

If your part is surrounded by nothing but thin air, it doesn't matter.

You have to think in terms of "fit".

So, once again, what is the tolerance on the mating part and what kind of relationship between the two you want to achieve?

"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future

RE: How much would be differenct between these two types of tolerating ?

Checker has it right- the tolerances for an ISO fit aren't 'arbitrary'- they are based on a fit type and a size window. Pick your fit type, specify the code. Leave it to your machinist to look up the tolerance in the chart (i.e. your dimension should read <diameter symbol> 78 h7, NOT <diameter symbol> 78 h7 +0.00 -0.03)

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