The magnetic filter is composed of a strong magnetic material with high coercivity and a blocking filter screen. Its adsorption force is ten times that of general magnetic materials. It has the ability to adsorb micron-sized ferromagnetic contaminants under instantaneous liquid flow impact or high flow rate conditions, and can overcome the re-adsorption of ferromagnetic contaminants washed down under high-speed and large impact, thus avoiding the seizure or wear of hydraulic components and extending the service life of hydraulic components and hydraulic systems, enhancing the reliability of the hydraulic system. Its center is a cylindrical magnet, surrounded by a non-magnetic material cover, with several iron rings connected by copper bars, maintaining a certain gap between each iron ring. When ferromagnetic impurities in the hydraulic medium pass through the gap between the iron rings, they are adsorbed on the iron rings, thus playing a filtering role.

To facilitate cleaning, the iron ring is divided into two halves. When impurities block the gap, the iron ring can be removed for cleaning and then reinstalled for repeated use. The magnetic filter can also be combined with other filter materials to form a composite filter for use in paper filter on the return oil line. The filter paper core is made of an inner and outer cylinder and an oil filter paper sandwiched in between. The inner and outer cylinders are rolled from thin steel plates, with many oil-through round holes punched on the plates; the filter paper is folded into a star shape to increase the flow area. The central rod of the filter core is equipped with many magnetic rings and nylon spacers to form a magnetic filter core.