This Standard has been prepared as a guide to the factors that contribute to uncertainty in the calibration of screw thread gaging devices. The reference section at the end of this Standard provides sources on how to compute uncertainty values. This Standard is intended to provide the following: (a) an explanation of measurement uncertainty and the factors that contribute to it (b) characteristics of the equipment required for thread gage calibration (c) guidance in the application of measurement uncertainty (d) methods to resolve measurement disputes This standard supersedes, replaces, and renders obsolete the B1-1993 Technical Report.