Description / Abstract:
This document addresses AS8879 thread inspection issues relating
to selection, usage and capability of gages. It addresses the
selection of calibrated measurement gages, the need for defined
quality metrics, the methodology of determining the appropriate
guardband factors, and the minimum inspection requirements for
single element pitch diameter gages.
Users of this document shall apply the information described
herein for the evaluation of the capability of their measurements
based on the measurement consumer risk. It involves the analysis of
the measurement (product) distribution and biases of both the
product and measurement system distributions. It protects the
consumer from the worst case distribution results.
A whitepaper has been developed to provide supporting
documentation and the rationale used in the development of this
standard. This whitepaper will be published by the SAE as an
Aerospace Information Report (AIR6553).
This document recommends the use of ASME B1.2 "Gages and Gaging
for Unified Inch Screw Threads" or IFI 301 "Gage Calibration
Requirements and Procedures for Thread Gages" as guides for
establishing the minimum calibration requirements for all types of
thread gages.