Our own, high quality cylinder tubes are made from Fe510 steel with the internal bore honed and polished to an exceptionally smooth surface of Ra < 0.4 micrometers. All cylinder tubes are subjected to individual inspection by quality control prior to use. The piston rods are made to the same high standards as the cylinders and are hard chrome plated to a thickness of > 25 urn. Hose break rupture valves are built into the bottom of the cylinders To reduce corrosion, loss of oil, and contamination, a drainhose is connected from the cylinder back to the tank (except S,. types). The safety factor by cylinder stress calculations is 1,8. Pressure hoses comply to main european standards.