Separation of single action of large tonnage hydraulic jack is specially designed for lifting and maintenance, optional sloping base in order to reduce the risk of damage to the lateral pressure and stroke limitation safety valve to ensure that the piston only extends to the rated stroke length Characteristic Part of the piston piston rod in welding copper, surface hard chromium plating, never cylinder, abrasion resistance Integral dust preventing plunger ring over stretching Partial load 10% without damage to the cylinder