Master Setting Ring For comparative gaging, calibration and the setting of internal measuring tools. Specifications include... 0.225" Size + 0.00005" Accuracy 0.000015" Taper / Ovality Features include... Made from oil hardened non-shrinking steel Hardened and tempered to 62 RC Actual dimensions duly etched Cryogenic treatment for long-term dimensional stability Calibrated at 20?§ C under standards room conditions
