How does magnetic filtration Work?

Magnetic Filtration is possible through the principle of magnetic attraction of ferrous particles. High intensity magnets (see sidebar) are placed inside of a stainless steel metal rod, and the rod is placed in a larger metal unit, Y-Strainer, or fitted into a canister. Once installed in the correct part of the equipment, the fluid flows through the metal unit containing the stainless steel metal rod without experiencing flow restriction. All of the equipment’s fluid passes around the rod, where more than 99% of ferrous particles down to sub-micron level are removed. The magnetic rod also collects non-ferrous particles through the principle of static adhesion.

Molecules typically have a neutral charge. But the flow of fluids and gas creates the right conditions for static electricity. When ferrous and non-ferrous materials are carried through a system, static adhesion attracts them to each other. This process is how OEI is able to capture non-ferrous contaminants.

The rod collects both ferrous and non-ferrous contaminants, until you are ready to clean it. Cleaning the OEI Magnetic Filtration unit is incredibly easy; simply remove the top cap connected to the stainless steel rod and wipe the rod clean.

Magnetic Filtration can be used to remove up to 99% of both ferrous and non-ferrous contaminants from all types of industrial fluids. Modern equipment component tolerances are as follows: engines are under 8 microns, bearings are under 3 microns and hydraulic system components are under 1 micron. Yet, the ISO standards for cleanliness start analysis at 4 microns and go up, therefore they are not providing all the information to identify possible severe contamination issues. In order to protect equipment components filtration under 4 microns is vital; and traditional full flow filtration technology fails to capture contaminants below 10 microns. This inability to filter contamination under 4 microns, results in 80% of all equipment failures. 

OEI Magnetic Filtration units can be used as a complete replacement to your existing filters, can work with existing filters, or can clean fluid lines that have no filtration.

Magnetic filtration improves equipment efficiency and reliability for all industries including: oil and gas, manufacturing, mining, transportation, marine, construction, pharmaceuticals, chemical processing, food production and more.

There are 4 common types of Magnets:

Aluminum-Nickel-Cobalt: Low strength magnets used for basic manufacturing

Ferrite- The horseshoe/refrigerator magnets at home

Samarium-Cobalt: High strength magnets rarely used due to structural limitations

Neodymium: Highest strength magnets in the world

Learn more about Magnets

How Traditional Filters Work

Traditional Oil Filter


In a traditional oil filter, oil flows into the filter through the bottom, where it then flows through the paper media inside the filter and out the bottom plug. This type of oil filter has a bypass valve, so when the filter clogs it directs unfiltered oil to the engine so it won’t starve. Traditional oil filters do not provide adequate protection for your engine, they are unable to filter damaging contaminants smaller than 10 microns, and when the filter is clogged it releases dirty oil into your equipment.

How Magnetic Filters Work

Magnetic Filtration

(Image: Machinery Lubrication)

Fluid flows in through the bottom of the unit and past a strong magnetic field. The contaminants collect on a stainless steel rod encasing the magnets. Because of the high dirt holding capacity of OEI magnets, they will never ‘clog’ as  ferrous and non-ferrous contaminants continue to collect at the many attraction points. Radial field magnetic technology casts a wider and stronger  field, so there is no escape – fluid passing through OEI filters is NEVER left unfiltered. Radial Field Magnetic Filtration collects contaminants under 1 micron to over 100 microns, so you capture all sizes of harmful contaminants.

OEI Magnetic Filter Results

One Eye Industries Magnetic Filter Collection


The picture above shows ferrous and non-ferrous contaminants trapped on an OEI Magnetic Filter Rod.

Advantages of Magnetic Filtration

  • Filter contaminants from below 1 micron to above 100– Using Rare Earth Magnets, specialized design, and our patented production method, our Magnetic Filters are able to collect ferrous and non-ferrous contaminants from under 1 micron to above 100 microns in size.
  • Easily clean and reuse– Simply remove the Magnetic Rod from the Magnetic Filter, wipe clean with a rag or sample collection cloth and replace back in the filter.
  • Reduce consumable and disposable costs–  Stop paying disposal costs for your used filters.
  • Create cost efficiency– The cost of removing a gram of particles from the oil with magnetic technology is low compared to disposable filters.
  • Limited flow restriction– Unlike conventional filters, OEI magnetic filters do not significantly increase flow restriction (pressure drop) as they load with particles. While conventional filters can go into bypass when they become plugged with contamination, magnetic filters (including mag-plugs and rods) continue to remove particles and allow clean oil flow. Most diesel and gasoline engines provide no indication of a filter that has gone into bypass. In such cases, the oil may flow for an extended period of time without being filtered.
  • Extend filter life– OEI Magnetic Filtration products are designed to last upwards of 15 years and have proven themselves in the field.
  • Reduce risk of oil oxidation– Iron and steel particles promote oil oxidation by their catalytic properties. Premature oil oxidation can lead to varnish, sludge and corrosion. As such, using magnetic filters to continuously and efficiently remove iron and steel particles should have a positive impact on oil service life, and over time, reduce oil consumption if oil is changed on condition.
  • Identify wear particles– Wear particle analysis can be used as a Predictive and Preventative maintenance tool by identifying early component wear and sources of contamination.
  • Easily perform spot checks for wear– Magnetic Plugs and Rods can be removed for visual inspection (daily, weekly, etc.) without stopping the machine or removing a filter. They provide the dual service of contaminant removal and condition monitoring (from the density of wear particles observed).
  • Filter without oil flow– Many machines are lubricated by oil splash, bath, flingers, slingers and paddles. Without access to a pump and oil flow, conventional onboard filters cannot be used to keep the oil clean and optimize machine reliability (reduce wear) and lubricant service life (reduce oil oxidation). However, Magnetic Plugs and Rods do not require oil to flow in pipes and lines. They require the oil only to agitate and circulate in a sump, reservoir or oil pan. This movement causes these particles to migrate to a loading surface of the Magnetic Filter.
  • Filter gravity flow drain lines–Due to the lack of oil pressure, it is nearly impossible to locate fine filtration on gravity drains to catch wear debris before it enters the reservoir. However, magnetic filters, rods and plugs do not restrict flow, enabling particles to be quickly and conveniently removed directly in oil drains.