NR.280 UNI 5739 Hexagon head screws fully threadedM20 L=105 UNI 5739 cl 12.9 HDG NR.280 UNI 5588 Hexagon nuts M20 UNI 5588 cl12 HDG NR.280 UNI 5589 Thin nuts M20 cl12 (or cl 10) HDG