K2901 Class ZZ No-Go Pin Gauge Material Steel Finish Black Oxide Diameter 0.4910 in Diameter Increment 0.0005 in Diameter Range 0.0610 in to 0.5005 in Diameter Sub-Range 0.4755 in to 0.5005 in Dimension Type Inch Gauge Type No-Go (Minus) Included Certification Certificate of Accuracy with NIST Traceability Surface Finish 10 Microinch or Better Tolerance 0.00020 in Tolerance Class ZZ Hardness RC 60/65 Long Form Calibration Certificate No Overall Length 2 in Standards ISO 17025