Threaded Plug Gauge, Dimension Type Inch, Gauge Type Go (Plus), Handle Design Member Only, Included Handle Not Applicable, Thread Class 2A, 3B, Thread Size 5/16 In.-18, Thread Type UNC, Tolerance Class X, Gauge Finish Chrome Plated, Gauge Length – Go Member 1/2 in, Gauge Material Tool Steel, Hardness RC 70-72, Included Certification Certificate of Accuracy with NIST Traceability, Long Form Calibration Certificate No, Pitch Diameter – Go Member 0.2764 in, Standards ASME B1.2