J5721 Class X Go Pin Gauge Material Steel Finish Uncoated Diameter 0.3410 in Diameter Increment 0.0001 in Diameter Range 0.2811 in to 0.4060 in Diameter Sub-Range 0.3401 in to 0.3450 in Dimension Type Inch Gauge Type Go (Plus) Included Certification Certificate of Accuracy with NIST Traceability Surface Finish 4 Microinch or Better Tolerance 0.00004 in Tolerance Class X Hardness RC 60/65 Long Form Calibration Certificate No Overall Length 2 in Standards ISO 17025