Threaded Plug Gauge, Dimension Type Metric, Gauge Type Go (Plus), Handle Design Member Only, Included Handle Not Applicable, Thread Class 6H, Thread Size M20 x 2.50, Thread Type Metric, Tolerance Class X, Gauge Finish Chrome Plated, Gauge Length – Go Member 22.20 mm, 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 18.38 mm, Standards ASME B1.16M