... 20cr,40Cr,20CrMo,16mn,ST35, ST37,ST37.4,ST45,ST52 and etc.TechnicalCold rolledCertificateISO 9001:2008Packing Export standard seaworthy packing or ... used for physical construction, hydraulic installation, auto parts,sleeves,and etc Contact personMs Daisy PLS contact me at any time ... astm a572 gr.50 welded steel tubeWe are direct producer and supplier, if you have any question, pls contact me ...