(1) EN 1999-1-1 gives basic design rules for structures made of wrought aluminium alloys and limited guidance for cast alloys (see section 3). NOTE Minimum material thickness may be defined in the National Annex. The following limits are recommended - if not otherwise explicity stated in this standard: - components with material thickness not less than 0,6 mm; - welded components with material thickness not less than 1,5 mm; - connections with: - steel bolts and pins with diameter not less than 5 mm; - aluminium bolts and pins with diameter not less than 8 mm; - rivets and thread forming screws with diameter not less than 4,2 mm