DIN 13-3
DIN 13-3 ISO general purpose metric screw threads - Part 3: Nominal sizes for 0.5 mm fine pitch threads; nominal diameter from 3.5 mm to 90 mm
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 11/01/1999
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 11/01/1999