... UsageApplicable to hydraulic pressure, pneumatic cylinder,oil pump barrel, motor body, transmission shaft, etc.Quality Standard DIN 239 ... SAE 1026, SAE4130,SAE4135, SAE4140, 27SiMnSize Processing Cylinder diameterLength /mmStraightnessSize accuracyWall thickness/mmInner boreroughnessCold-drawnID28~OD400≤12M0 ... etc), Exterior Size InspectionSKYPE: samsonhuang22 hydraulic cylinder tube st52 din2391