The hydraulic cylinder is the actuator in the hydraulic transmission system, which converts the hydraulic energy into mechanical energy. It is made of cylinder piston piston rod cylinder head seals and so on. It can be straight reciprocating motion or swing type Single action or double action According to the structure can be divided into piston type, plunger type, multi-stage telescopic sleeve type; For withstand pressure it can be 16Mpa 25Mpa 31.5Mpaand son on. For Material there are different material for components Cylinder aluminium alloy No.45, 20 carbon structural steel, alloy steel Snap Rings#45 carbon structural steel, spring steels. Piston aluminium alloy 45 carbon structural steel, alloy ball Piston rod: #45 carbon structural steel, alloy ball Guide sleeve aluminum alloy 45 carbon structural steel Lug 45 carbon structural steel, cast steel Seal NBR PU and PTFE Seals are very important for hydraulic cylinder, to maximize guarantee the good sealing performance of cylinder, and extend their service life.