Threaded Plug Gauge, Dimension Type Inch, Gauge Type Go (Plus), Handle Design Member Only, Thread Class 2B, 3B, Thread Size 5/16 In.-32, Thread Type UNEF, 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, Pitch Diameter - Go Member 0.2922 in, Standards ASME B1.2, Thread Direction Right Hand