http://www.steeltubeschina.com..../carbon-steel-tube/g Auto shock absorber innder cylinder Telescopic Cylinders Size Range: ID.: 20-650mm W.T.:1-50mm L:max12000mm Steel Grade: E155, E195, E235, E275, E355. S45C Steel Grade And Chemical Compositions Steel GradeCSiMnPS Steel NameSteel Numbermaxmaxmaxmaxmax E1551.00330.110.350.700.0250.025 E1951.00340.150.350.700.0250.025 E2351.03080.170.351.200.0250.025 E2751.02250.210.351.400.0250.025 E3551.05800.220.351.600.0250.025 Heat Treatment Method: +Cc, +LCc, +SR, +Ad, +N Note: Special steel grade is also available, according to customer request. Please specify the steel grade and heat treatment mothod when sending the enquiry! For Application Of: Test Methods: Tensile test Flattening test Drift expanding test Dimensional inspection Roughness measurement Visual examincation Not-destructive testing a. Test for longitudinal imperfections- - Eddy current test - EN10246-3, level E3 - ultrasonic testing - EN10246-7, level U3 b. Leak-tightness - Non-destructive testing for verification of leak-tightness shall be carried out in accordance with EN10246-1 EN10305 Consists of the following Parts under the general title " Steel tubes for precision applications - Technical delivery conditions " Part 1: Seamless Cold Drawn Tubes Part 2: Welded Cold Drawn Tubes Part 3: Welded Cold Sized Tubes Part 4: Seamless Cold Drawn Tubes for Hydraulic and Pneumatic Power Systems Part 5: Welded and Cold Sized Square and Rectangular Tubes Part 6: Welded Cold Drawn Tubes for Hydraulic and Pneumatic Power SystemsGas Cylinder Tube factory website:http://www.steeltubeschina.com..../carbon-steel-tube/g