Overview Reviews Product Description CERTIFIED COATED METAL PLATES Select the Standard that most closely matches the measuring range of your gage. All certified standards are supplied with a Certificate of Calibration traceable to NIST or PTB.Plate Diameter: 38 mm (1.5") Measurement Diameter: 25 mm (1") Discover our other Defelsko products. Product Videos Custom Field Product Reviews Write a Review Write a Review × DeFelsko Defelsko Ferrous Calibration Standards Rating * Select Rating 1 star (worst) 2 stars 3 stars (average) 4 stars 5 stars (best) Name Review Subject * Comments *