What steel are used in hydraulic cylinders?

Hydraulic cylinders mainly include cylinder tube, piston rod, cylinder head, and piston. What kind of steel should be used? Let me tell you about the steel used in hydraulic cylinders.

      1. Cylinder head

      Castings for low pressure, HT300 gray iron for medium and low pressure, 35 and 45 steel for medium and high pressure.

      When the cylinder head itself is the guide sleeve of the piston rod, cast iron should be used as far as possible. At the same time, brass, bronze or other wear-resistant materials should be melted on the guide surface. If the structure of the guide sleeve is pressed into the cylinder head, the guide sleeve should be wear-resistant cast iron, bronze or brass.

      2. Cylinder

      Commonly used materials are 20, 35, and 45 seamless steel pipes. The steel pipes are honed or rolled to meet the roughness requirements within 0.4μm. The low pressure oil cylinder can be made of No. 20 steel pipe, and the high pressure cylinder can be made of No. 45 steel pipe.

      3. Piston

      Commonly used materials are wear-resistant cast iron, gray cast iron (HT300, HT350), steel and aluminum alloy.

      The coaxiality tolerance value of the piston and the piston rod should be 0.03mm.

      4. Piston rod

      There are two types of piston rods: solid rod and hollow rod. One end of the hollow piston rod needs to be reserved for welding and heat treatment. The material of the solid piston rod is 35, 45 steel, and the material of the hollow piston rod is 35, 45 seamless steel pipe.

      After rough machining, the piston rod is quenched and tempered to India to be 229~285HB. If necessary, it is subjected to high frequency quenching to achieve a hardness of 45~55HRC.