Summary again...
While the previous discussion was interesting as to wether Philip Holland should be hit with a major NC, minor NC or given a pass, the original question still remains.
Philip Holland said:
Thread plug gauge failed calibration - Must I remeasure everything measured with it?
When thread gages are returned from calibration there will be some that need replacing because they went out-of-tolerance since their previous calibration. This is an unavoidable and inevitable situation. The problem now is wether or not to take remedial action against product produced between the previous calibration and the failure.
The quality engineer must now make the decision about product bought off before the gauge was replaced. The logic used by the engineer must be well thought out and well documented. To assist in this process the following logic is presented. The quality engineer, may use this logic or deviate from this logic as long as the decision can justified to company management.
Philip Holland said:
Have been receiving several go and no go gauges back from calibration that are out of calibration by virtue of having grown. Last audit, the auditor randomly picked a gauge that had failed the last calibration. Well, I had replaced the offending member but had not documented any further action. It is my belief that as a quality engineer, I should be able to make a judgement as to whether an audit of product bought off by this gauge is warranted. Thread gauges are used in IQA and to verify that correct inserts are installed in molded product.
In this situation one of two possible conditions could exist. The original question did not specify which gage went oversize.
1. Thread Work Plug Gage GO member failure for oversize: A GO/NOGO Thread Work Plug Gage was used to inspect product. Only product that the gage passed is in question. The GO member grew during the production run. The GO member is smaller than the NOGO member. The GO member checks the maximum material condition. When the GO member grew it reduced the manufacturing tolerance, and may have failed some good product. Used in conjunction with the NOGO member, the pair would not have allowed any rejected product to pass inspection. There is no need to do a product recall. The only required action is to replace the offending member and document the decision.
2. Thread Work Plug Gage NOGO member failure for oversize: A GO/NOGO Thread Work Plug Gage was used to inspect product. Only product that the gage passed is in question. The NOGO member grew during the production run. The NOGO member is larger than the GO member. The NOGO member checks the minimum material condition. When the NOGO member grew it may have passed some bad product. The required action is to replace the offending member, do a product recall and document the decision.