... square steel pipe 1.Thickness:0.6 - 10 mm 2.Size:15*15-400*400mm 3.Grade:Q195,Q215,Q235,Q345 Square Steel ... frequency weldedSteel grade :Q195,Q215,Q235,Fe310,Fe360,St33,St330,St37-2,SS330,SS400,ASTM1010,ASTM1017,ASTM1020Manufactured to meet ISO9001 ... airport structure ,sports apparatus and automotive partsPacking :In square bundlesO,D.(mm)W,T.(mm)O.D.(mm ... the world in long run . black square steel tube