Pipe Thread Ring Gauge, Long Form Calibration Certificate No, Material Tool Steel, Dimension Type Inch, Gauge Type L-1, Pitch Diameter. 77843 In., Thread Class L1, Thread Length Not Applicable, Thread Size 1/2 In. -14, Thread Type NPT Plug Gauge, Finish Uncoated, Gauge Design Solid, Hardness RC 60-62, Included Certification Certificate of Accuracy with NIST Traceability, Standards ASME B 1.20. 1, Tolerance Class X