DS EN 3328:2008 Aerospace Series - Bolts, Double Hexagon Head, Close Tolerance, Medium Thread Length, In Heat Resisting Steel Fe-Pm38 (Fv535), Uncoated - Classification: 1000 Mpa/550 Degree C Defines the dimensions of the uncoated double hexagon head bolts, close tolerance, with MJ-thread, medium thread length, in heat resisting steel FE-PM38 for aerospace applications.