Aerospace series – Sleeves – Wall thickness 0.5 mm, for fasteners with reduced countersunk head; Text in German and English
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 03/01/2017

Aerospace; sleeves; wall thickness 0.5 mm, for fasteners with reduced countersunk head
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 12/01/1987