Have you ever been rejected for a reference dimension being out of tolerance?

[bobdoering]

Re: Reference Dimension

Sorry in the 18 years I have been working as a inspector / Quality manager I have never seen a tolerance applied to a (ref) dimension.

Good point - no tolerance makes for a tough rejection decision. I have had Japanese transplants ask for reference dimensions to be measured and reported on ISIR, but not rejected for them. Shoot, if it is going to be a rejectable dimension, just have them pull off the parenthesis and quit teasing you!

 

[qmindiana]

We have a customer that tells us to take the controlling GD&T, divide it by 2 and use that as the reference dimension tolerance. They sent back a PPAP becuase we didn't use this method.

 

[Wes Bucey]

Have you ever been rejected for a reference dimension being out of tolerance?

Yes, but I'm embarrassed to disclose WHICH of my "reference dimensions" was out of tolerance to trigger MY rejection (versus having a PRODUCT rejected.)

 

[Stijloor]

Re: No tolerances on drawing

Hi there, I was wondering if anyone has ever ran into a print that has no GD&T identified, no tolerances identified and no tolerances in the title block? Is there a standard tolerance that I should use: i.e. .x = ?mm, .xx=.?, .xxx=.?. Any help would be aprpeciated.

Thanks.

Nope. There's no "standard" for a nonconforming drawing. :mg:

That means that the drawing is up to whomever's interpretation. Which means that you will end up with a big mess.

Stijloor.

 

[qmindiana]

You mean it will be left up to the customers interpretation...... I believe I will have to drive it back to the customer and have them determine the tolerances up front to remove any ambiguity here.

Thanks for your input.

 

[Jim Wynne]

You mean it will be left up to the customers interpretation...... I believe I will have to drive it back to the customer and have them determine the tolerances up front to remove any ambiguity here.

Thanks for your input.

Stijloor's right. Any time there's something ambiguous in the requirements, you need to avoid guessing and ask the customer.

 

[MIREGMGR]

Do the customer's drawings or specs make reference to ANSI Y14.5 conformance or applicability?

Y14.5 defines a "reference dimension" as “A dimension usually without tolerance, used for information purposes only. A reference dim is a repeat of a dimension or is derived from other values shown on the drawing or on related drawings. It is considered auxiliary information and does not govern production or inspection operations.”

If they said that Y14.5 applied, your assumption was reasonable. Otherwise, I agree with those saying that ambiguity should have been detected and dealt with up front.

 

[Stijloor]

You mean it will be left up to the customers interpretation...... I believe I will have to drive it back to the customer and have them determine the tolerances up front to remove any ambiguity here.

Thanks for your input.

Accepting a contract including bad drawings is also a violation of 7.2.1 (Determination of requirements...) and 7.2.2 (Review of requirements....).

That's why ISO 9001 and also ISO/TS 16949 (I can not speak of other Standards) have this requirement to prevent this situation. The time to speak up is at the requirements review stage, not at or after PPAP submittal.

I wish you strength!

Stijloor.

 

[lostmanager]

Re: Reference Dimension

We had a drawing with a reference dimension callout for ID on a 10 SCH80 pipe, the print was right, but since it listed the ID as reference the inspector did not write it up for being .350 out of tolerance(oversized). Pipe was actually sch80s and ID was way to big, pipe was tagged wrong in inventory and since we didn't write a NCR for the ID being out, since it was REF, it got welded and now we must scrap. Engineering blaming QC and vice versa.