We have a supplier that has used a roll form tapping process on parts we specify a thread requirement of UNF 10-32 2B. My research on producing internal threaded parts using a roll formed tapping process indicates that we cannot specify a thread standard if we wish to allow the roll form process to be used which produces an inconsistent minor diameter. The minor diameter limit of size is clearly defined for the for threads produced to the UNF standard. The inspection method used by our supplier is to use a go no-go UNF 10-32 2B gauge only, which is why we received parts which the minor diameter measured .180? plus. Obviously an oversized drill was used. I would think we cannot specify a standard if we allow roll forming. I understand that a higher quality thread is produced, but how can I allow this process in a ISO 9001 controlled environment? Please help!