Special precision steel tube , widely used on automotive, hydraulic machine, precision Parts1.standard: DIN2391, EN10305, SAE J5242.Material: ST35,ST37,ST52, 10#,20#,45# ,SAE1010,SAE1020,SAE1045 etc3.size:OD: 5.0-30MM WALL: 0.7-7.0MM LENGTH: 1-12meter4.packing: seaworthy packing