DS EN 3052:2009 Aerospace Series - Bolts, Normal Hexagonal Head, Close Tolerance Normal Shank, Short Thread, In Heat And Corrosion Resisting Steel, Passivated - Classification: 1100 Mpa (At Ambient Temperature)/425 Degree C Defines the characteristics of bolts, normal hexagonal head, close tolerance normal shank, short thread, in heat and corrosion resisting steel, passivated.