Threaded Ring Gauge, Long Form Calibration Certificate No, Material Tool Steel, Dimension Type Inch, Gauge Type Go/No-Go (Plus/Minus), Pitch Diameter 0.8412 (Go), 0.8368 (No-Go), Pitch Diameter - Go Member 0.8412 in, Pitch Diameter - No-Go Member 0.8368 in, Thread Class 2A, Thread Length 11/16 in, Thread Size 7/8 In.-20, Thread Type UNEF, Compatible Holder Size 5T, Finish Uncoated, Gauge Design Adjustable, Hardness RC 60-62, Included Certification Certificate of Accuracy with NIST Traceability