Stainless steel fittings for the food and chemical industry – Part 1: Hygienic screwed pipe connection, short type
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 04/01/2011

Stainless steel components for hygienic applications in the food and the chemical industries – Part 1: Connections
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 08/01/2017