Threaded Ring Gauge, Long Form Calibration Certificate No, Material Tool Steel, Dimension Type Inch, Gauge Type Go (Plus), Pitch Diameter 0.2752 in, Pitch Diameter - Go Member 0.2752 in, Thread Class 2A, Thread Length 11/32 in, Thread Size 5/16 In.-18, Thread Type UNC, Compatible Holder Size 2T, Finish Uncoated, Gauge Design Adjustable, Hardness RC 60-62, Included Certification Certificate of Accuracy with NIST Traceability, Standards ASME B1.2, Tolerance Class X