Magnets for hoppers
Our range of magnetic separators also includes these special magnets for hoppers. Hopper magnets (also known as magnetic in-line separators for hoppers or feeders) are a vital first line of defense in any production line handling bulk materials — powders, granules, pellets, or bulk solids. Their purpose is simple, but essential: to catch and remove ferrous contaminants before materials even enter the processing equipment, ensuring smoother flow and protecting downstream machines from damage.
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Who Should Use Hopper Magnets
Our magnetic hopper solutions are a strong fit for:
- Producers of food and feed – grains, flour, powders, pellets.
- Plastics and rubber processors – granules, regrind material, masterbatch powder.
- Chemical and mineral processing – powders, concentrates, bulk mineral input.
- Recycling and waste processing – mixed bulk, reused plastics, compost, bulk refuse.
- Bulk-material handling operations – storage hoppers, feeders, silos, transport lines.
1Measure the hopper opening first
A hopper magnet works by covering the opening as fully as possible, so the granulate has to pass through the magnetic field rather than around it. Take the internal dimension at the point where the magnet will sit, not the outer dimension of the hopper.
Round versions are stocked in diameters 100, 150, 200, 250, 300 and 350 mm. If the free cross section is left uncovered on one side, fine iron particles will find that route every time.
2Set the temperature rating from the real process
Two lines are stocked: standard versions rated up to 80 °C and versions rated up to 120 °C. The higher rating is for hoppers fed with dried or preheated granulate, hoppers sitting directly on a heated barrel, or machines where the drying unit warms the material on the way in.
Once a magnet is overheated it loses force permanently and no amount of cleaning brings it back, so if in doubt take the higher rating.
3Compare strength on the stated figures
The stronger stocked versions state 13,500 Gs and 95 N, while the economy MDN models sit lower, around 4,530 Gs to 6,810 Gs with pull forces of roughly 31 to 36 N.
For visible steel fragments and regrind contamination the economy line does the job. For fine iron dust and abraded particles from mills, screws and regrinders, take the stronger design, since those particles are what actually damage nozzles and hot runners.
4Choose the cleaning method before you buy
The EKO versions are cleaned simply by wiping the magnet down by hand. The better designs let you pull the magnetic cores out of the tubes, and the captured iron then releases away from the material flow, which is far cleaner and much faster during a shift change.
If the magnet is cleaned over an open hopper, the difference matters: wiping over the intake risks dropping the captured contamination back into the material.
5Check the fit against the machine, not the model code
The range covers UP models in sizes S, M, L and XL for injection moulding machine hoppers and MDN models from 100 to 300 in MVM, STEFF and ULT designs. The codes come from the original machine fittings, so two hoppers with similar model names can still differ in the seating.
Confirm the seating diameter, the depth available under the lid and the way the magnet is held in place before ordering.
6Know where a hopper magnet is the right tool
It suits plastics processing (granulate, regrind, masterbatch), food and feed production (grain, flour, powders, pellets), chemical and mineral powders, recycling lines and bulk handling at feeders and bagging stations.
Where a much larger capture surface or a finer barrier is needed, a magnetic grid or a flow-through separator is the better answer, and the hopper magnet then stays as the first stage.
Tip: Send a photo of the open hopper together with the internal diameter, the material and the working temperature. That is normally enough for us to confirm the size and the version without a site visit, and it avoids the most common return, a magnet that is one size too small.
Related categories to the Magnets for hoppers category
- Magnetic separators
- Magnetic grids
- Magnetic rods
- Magnetic plates
- Separator with telescopic grates
- Rotational separators
- Plate magnetic separator
- Magnetic drum
- Flow magnetic separators
- Magnetic separation vessel
- Magnetic dust traps
- Magnetic swarf collectors
- Heat-resistant magnets
- Magnetic handling aids
- Magnetic sweepers
- Industrial magnets
Frequently asked questions about hopper magnets
Take the internal dimension of the hopper at the point where the magnet will sit and choose the closest size that covers the opening as fully as possible. Round versions are stocked in 100, 150, 200, 250, 300 and 350 mm. A magnet that leaves a free gap at the side lets fine particles bypass it, which is the single most common reason a hopper magnet appears to underperform.
The 80 °C version covers hoppers running at ambient temperature with cold granulate. Choose the 120 °C version where the material is dried or preheated, where the hopper sits directly on a heated barrel, or where a dryer feeds warm granulate in. Overheating weakens the magnet permanently, so where the real temperature is uncertain the higher rating is the safer choice.
The economy versions are wiped down by hand. Stronger designs allow the magnetic cores to be pulled out of the tubes, so the captured iron releases away from the material and can be collected rather than dropped back into the hopper. Clean it at every material change as a minimum, and more often when processing regrind or contaminated input.
A hopper magnet is designed to sit in the opening of a hopper or feeder and covers that opening. A magnetic grid is a frame of parallel magnetic rods with a considerably larger capture surface, used where the material has to pass through a finer barrier or where throughput is higher. Many operations use both: the hopper magnet as the first stage and a grid in front of the critical machine.
Yes, they are used in food and feed production as well as in plastics processing, wherever grain, flour, powders or pellets pass through a hopper, feeder or bagging station. For a specific plant, confirm the required design and documentation with us before ordering so that the version matches your hygiene and inspection requirements.
The range covers UP models in sizes S, M, L and XL and MDN models from 100 to 300 in MVM, STEFF and ULT designs, which corresponds to common machine fittings. Model names alone are not a guarantee of fit, so check the seating diameter, the depth available under the lid and the way the magnet is secured. Send us a photo and the internal diameter and we will confirm it.
A hopper magnet is the cheapest component in the whole line and the one that decides whether an iron particle reaches the injection nozzle. We stock round versions from 100 mm up to 350 mm, in temperature ratings up to 80 °C and up to 120 °C, from economy MDN models to stronger designs stating 13,500 Gs and 95 N, plus UP versions in sizes S to XL for injection moulding machine hoppers. Because we manufacture industrial separators ourselves, we can also confirm whether a hopper magnet is enough in your case or whether the load belongs on a magnetic grid or a flow-through unit. Send us the hopper diameter, the material and the working temperature and we will size it for you.
