Pipe Thread Ring Gauge Long Form Calibration Certificate No Material Tool Steel Dimension Type Inch Gauge Type Go/No-Go (Plus/Minus) Pitch Diameter 1.5816 (Go) 1.5756 (No-Go) Pitch Diameter - Go Member 1.5816 in Pitch Diameter - No-Go Member 1.5756 in Thread Class 2A Thread Size 1 1/4 In.-11 1/2 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