ASTM A500 hollow section hollow section manufacturers 1.Size:20*20-400*400mm & 10*20-200*400mm. 2.WT:1.0-15.75mm. 3.Standard: API 5L,ASTM A106,ASTM A53,ASTM A500,EN10210,JIS G3466 etc. 4.Material:API 5L Gr.B,A106 Gr.B,A53 Gr.B,S355,ST52,STKR400,STKR490,Q235,Q345,16Mn etc. ...