DIN 2245-2
DIN 2245-2 Geometrical product specifications (GPS) - Limit plug gauges - Part 2: For holes over 40 mm up to 65 mm nominal diameter
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 07/01/2008
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 07/01/2008