Black Oxide-Coated Pin Gauge Set Material Tool Steel Finish Black Oxide Diameter Increment 0.001 in Diameter Range 0.2510 in to 0.5000 in Gauge Type Go (Plus) Number of Gauges 250 Overall Length 2 in Surface Finish Uncoated Tolerance 0.0002 in Tolerance Class ZZ Hardness RC 60/65 Included Certification Certificate of Accuracy Long Form Calibration Certificate No Standards ISO 17025 2005 Dimension Type Inch