Tube piston rod thread f1 force 12 4 M4/m3 10-200 n 15 6 M6 40-400 n 18 8 M6/m8 50-600 n 19 8 M6/m8 50-750 n 22 10 M8 100-1500 n 25 10/12 M8 100-2000 n 27 10/12 M10 100-3000 n 28 12/14 M10 100-3000 n By carton, each adjustable gas spring with water-proof plastic bag.