I have just received 2 PPAP submissions from a new supplier for two different size steel tubes. Going through the GR&Rs I noticed that the Inside Diameter GR&R for both size tubes are identical, number for number. I have looked for the gauge that they have listed on the report (Mitutoyo 3 pt bore gauge Model# 92865) but after contacting Mitutoyo :evidence: there is no 92865 (they said that number might be a serial number off of the indicator).

The ID of the 2 tubes are 42mm and 53mm (approx). Mitutoyo :evidence: told me that they do not have a bore gauge which covers both dimensions at the same time without changing gauging heads. This looks like a cookie cutter GR&R to me. So the question is; would you accept these GR&Rs knowing that they probably were not done on the material listed but done on a similar material with an unknown diameter.
To boot the % R&R was 17.1%

:thanks:

I have just received 2 PPAP submissions from a new supplier for two different size steel tubes. Going through the GR&Rs I noticed that the Inside Diameter GR&R for both size tubes are identical, number for number. I have looked for the gauge that they have listed on the report (Mitutoyo 3 pt bore gauge Model# 92865) but after contacting Mitutoyo http://elsmar.com/Forums/images/smilies/evidence.gif there is no 92865 (they said that number might be a serial number off of the indicator).

The ID of the 2 tubes are 42mm and 53mm (approx). Mitutoyo http://elsmar.com/Forums/images/smilies/evidence.gif told me that they do not have a bore gauge which covers both dimensions at the same time without changing gauging heads. This looks like a cookie cutter GR&R to me. So the question is; would you accept these GR&Rs knowing that they probably were not done on the material listed but done on a similar material with an unknown diameter.
To boot the % R&R was 17.1%

http://elsmar.com/Forums/images/smilies/thankyou.gif

You don't say whether the GR&R was performed on one of the parts in question or not. If so, and the same gage and operators are used on both parts, it might be OK. It also might be OK if the study was just performed on a similar part. If surrogate data was used, it should have been discussed with you beforehand. Some other observations:


Repeatability is usually an issue with bore gages. My guess is that most of the 17% is due to it. 17% might be OK, depending on the application. Note that the fact that the supplier is reporting 17% is evidence that the results weren't fudged; fudged results will almost always be < 10%.
If the operators are responsible for setting the gage prior to use, they should also set it prior to the GR&R study. If someone else sets the gage, that person should set it for the study.
Is a bore gage necessary? There's an awful lot of variability involved, and the ID isn't going to be consistent along its entire length. Can pins be used instead?
Is the probe being used long enough to check at least half the entire lengths of the parts? There's no point in using a bore gage if the entire length of the part isn't being checked, in most cases.
Be aware that there may be conditions at the ends of the bore that the gage might not detect. The probes aren't fixed (i.e., they "telescope") so in inserting the gage it's easy to bypass displaced material at the ends.

The GR&R # of 17% sounds entirely possible using a 3 pt. bore gauge. I would ask them what the actual model # of the gauge was. It's possible they have said this gauge is #?????? and confused it with the actual model #.

One way to find out: Phone them and ask! :)