Pipe Thread Ring Gauge, Long Form Calibration Certificate No, Material Tool Steel, Dimension Type Inch, Gauge Type 6-Step, Thread Size 1/16 In.-27, Thread Type NPTF, Finish Uncoated, Hardness RC 60-62, Included Certification Certificate of Accuracy with NIST Traceability, Standards ASME B1.20.5, Tolerance Class X