K7121 Class X No-Go Pin Gauge Material Steel Finish Uncoated Diameter 0.5107 in Diameter Increment 0.0001 in Diameter Range 0.5101 in to 0.6350 in Diameter Sub-Range 0.5101 in to 0.5150 in Dimension Type Inch Gauge Type No-Go (Minus) 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