... .3-1.0/1000 UsageApplicable to hydraulic pressure, pneumatic cylinder,oil pump barrel, motor body, transmission shaft, etc ... packingSteel GradeST52/E355, ck20, ck45, 34CrMo4, SAE 1026, SAE4130,SAE4135, SAE4140, 27SiMnSize Processing Cylinder diameterLength /mmStraightnessSize accuracyWall thickness/mmInner boreroughnessCold ... : samsonhuang22 honed tubes for hydraulic and pneumatic cylinder