... Straightness 0.3-1.0/1000 UsageApplicable to hydraulic pressure, pneumatic cylinder,oil pump barrel, motor body, transmission shaft, ... 34CrMo4, SAE 1026, SAE4130,SAE4135, SAE4140, 27SiMnSize Processing Cylinder diameterLength /mmStraightnessSize accuracyWall thickness/mmInner boreroughnessCold-drawnID28~OD400≤12M0 ... Size InspectionSKYPE: samsonhuang22 honed tubes for hydraulic and pneumatic cylinder