Pipe Thread Ring Gauge Long Form Calibration Certificate No Material Tool Steel Dimension Type Inch Gauge Type No-Go (Minus) Pitch Diameter 0.3689 in Pitch Diameter - No-Go Member 0.3689 in Thread Class 2A Thread Size 1/8 In.-27 Thread Type NPSM Finish Uncoated Hardness RC 60-62 Included Certification Certificate of Accuracy with NIST Traceability Standards ASME B1.20.1 Tolerance Class X