Class X Go Pin Gauge, Material Steel, Finish Uncoated Steel, Diameter 0.4291 in, Diameter Increment 0.0001 in, Diameter Range 0.4061 in to 0.5100 in, Diameter Sub-Range 0.4251 in to 0.4300 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