... high precision 2.good wear resistance 3.fine finish 4.Certificate ISO 9001:2008 Precision steel tube for shock absorber DescriptionDetails Precision steel tube for ... buyer's requestStandard GB/T3639, GB8162,GB8163, DIN2391 ASTM A519,A106 ,A179 A53,, EN10305-1,EN10305-4, ... 20CrMo,16mn,ST35, ST37,ST37.4,ST45,ST52 and etc.TechnicalCold rolledCertificateISO 9001:2008Packing Export standard seaworthy ...