PML
Magnetic Pulley
Magnetic Pulley
Starting from Rs.16,800
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Product Details
At a Glance
A magnetic pulley is a conveyor head pulley with a built-in magnet that continuously removes ferrous tramp metal (nails, wire, bolts) from bulk material as it passes over, with zero power draw and no separate housing. PML manufactures magnetic pulleys in high-intensity NdFeB (4,500 ± 500 Gauss) and low-intensity ferrite (1,200 Gauss) grades for conveyor-based material handling in steel, mining, cement, recycling and grain industries.
Every conveyor line carrying bulk material eventually picks up something it shouldn't — a stray bolt, a length of wire, a nail from a pallet. The PML Magnetic Pulley solves this at the one point in the line where it's cheapest to fix: the head pulley itself. Swap your standard head pulley for a magnetic one, and every stray ferrous object is pulled out of the material stream automatically, with zero power draw and next to no maintenance.
PML is one of India's established magnetic pulley manufacturers, supplying both high-intensity NdFeB (4,500 ± 500 Gauss) and low-intensity ferrite (1,200 Gauss) pulleys built into the drive end of your existing conveyor — no separate housing, no extra footprint.
How It Works
As material passes over the pulley, ferrous fines are held to the belt by the magnetic field until it reaches the underside of the pulley — well past where clean product falls away in its normal vertical drop. The captured tramp metal continues around, out of the field, and is collected separately in a chute or bin. No cleaning cycle, no downtime: separation happens continuously as the belt runs.
Where It's Used
Steel plant raw material handling, waste stream and recycling lines, feed and grain handling, mining and ore dressing, cement and coal handling plants, salt processing, glass, paper, refractory and mineral processing (including bauxite) — anywhere a conveyor discharge needs protecting from tramp iron. See our tramp metal removal for the steel industry or mining, cement & aggregates pages for more.
Reference installation: An 800mm diameter × 2250mm effective-length high-intensity magnetic pulley (4,500 ± 500 Gauss) is in service at Tata Steel's Kalinganagar plant, Odisha.
Key Advantages
- Zero Power Cost
Permanent magnets do the work — no electricity, no controls, no ongoing running cost.
- Full-Face Protection
The entire face of the pulley is magnetically active, so contamination is captured across the whole belt width, not just a strip.
- Simple Retrofit
Installs as a direct head-pulley swap — loosen the belt, remove the old pulley, fit the magnetic one. No new wiring or controls required.
- Built for the Application
Choose high-intensity NdFeB for fine, weakly-magnetic fines, or ferrite for larger tramp metal at lower cost.
Standard Range
| High-Intensity Magnetic Pulley (4,500–5,000 ± 500 Gauss, NdFeB, max. 80°C) | |||
|---|---|---|---|
| Pulley Diameter | Belt Width Range | Shaft Diameter | Model Series |
| Ø200mm | 350–950mm | Ø35mm | HMP 240–HMP 2100 |
| Ø300mm | 350–950mm | Ø45mm | HMP 340–HMP 3100 |
| Ø400mm | 350–950mm | Ø55mm | HMP 440–HMP 4100 |
| Ø500mm | 350–950mm | Ø65mm | HMP 540–HMP 5100 |
| Ø600mm | 350–950mm | Ø75mm | HMP 640–HMP 6100 |
Each diameter group is built in 13 belt-width increments (350mm to 950mm) with a total length matched to the belt, so there is a close-fit model for almost any conveyor. Low-intensity ferrite (1,200 Gauss) versions are available in the same diameter range for coarser tramp metal at lower cost.
What We Need for a Custom Pulley Quote
- Type of material being conveyed
- Conveyor belt width and speed
- Size and concentration of the expected contamination
- Burden depth on the belt
Frequently Asked Questions
Does the magnetic pulley need power?
No. It uses permanent magnets, so there's no electricity, wiring or running cost involved — only the mechanical drive that already turns your conveyor.
Will it fit my existing conveyor?
In most cases, yes — it's designed as a direct head-pulley replacement. Send us your belt width, pulley diameter and shaft size and we'll confirm or recommend a custom build.
High-intensity or low-intensity — which do I need?
High-intensity NdFeB (4,500+ Gauss) is for fine or weakly-magnetic contamination; low-intensity ferrite (1,200 Gauss) is a lower-cost option for larger, strongly-magnetic tramp metal like bolts and wire.
What pulley diameters are available?
200mm to 600mm in the standard high-intensity range, each built in 13 belt-width increments from 350mm to 950mm.
Is there a proven installation I can reference?
Yes — an 800mm diameter × 2250mm effective-length high-intensity pulley (4,500 ± 500 Gauss) is in service at Tata Steel's Kalinganagar plant, Odisha.
Why Buy From PML
- 65+ years of magnetic and separation engineering — Permanent Magnets Ltd has designed magnetic separation equipment for India's cement, mining, food and recycling industries for 65+ years.
- Made and tested in-house — pulleys, shafts and magnet assemblies are manufactured and quality-checked at our own facilities.
- Field-proven at scale — in service at major industrial sites including Tata Steel Kalinganagar.
- Magnetic calibration and audit services available after installation to verify field strength over time.
Need a custom diameter, belt width or shaft configuration? Enquire now and our engineering team will size the right pulley for your conveyor.
Why Magnetic Strength Drops in Ferrous Separators (and When to Replace)
Separation efficiency falls as magnetic strength decreases. Below are the most common causes of reduced field strength in NdFeB (neodymium) magnetic separation equipment, along with the warning signs that indicate a magnet or separator needs replacing.
Causes of Reduced Magnetic Strength
- Thermal demagnetization: Standard Neodymium-Iron-Boron (NdFeB) grades lose magnetic strength when exposed to temperatures above their rating — often starting at 80°C / 176°F for standard grades. Exceeding these limits causes a permanent loss of magnetic flux.
- Corrosion and core oxidation: NdFeB is highly iron-rich and oxidizes quickly. If moisture, washdown liquids, or corrosive chemicals breach the outer stainless steel cladding, the magnet swells, crumbles, and loses field strength.
- Mechanical damage and internal cracking: NdFeB is brittle. Dropping magnetic tubes during cleaning, or subjecting them to heavy equipment vibration, causes internal micro-fractures that break the continuous magnetic circuit.
- Strong opposing magnetic fields: A sufficiently strong opposing field can overcome a material's coercivity and flip or randomize its magnetic domain polarity. High alternating current (AC) electric fields, in particular, create powerful local alternating magnetic fields that rapidly scramble domain alignment.
- Material buildup ("air gap" effect): Accumulated fine iron on the surface acts as a barrier, pushing the active magnetic field further away from incoming material. Because magnetic force decays exponentially with distance, even a few millimetres of buildup severely reduces capture rates.
- Increased process velocity or burden depth: Running material too fast, or in overly thick layers, prevents fine ferrous particles from spending enough time in the peak magnetic field zone to be pulled out of the flow.
Signs an NdFeB Magnet or Separator Needs Replacing
- Drop in gauss rating: Annual or semi-annual gauss testing shows a permanent drop of 10–15% or more from the baseline specification.
- Bulging or "pillow" swelling: The protective stainless steel tube cladding looks warped, swollen, or cracked — a sign of internal oxidation where rust has expanded inside the shell.
- Dead spots along the field: Measuring with a gauss meter reveals localised spots with zero or drastically lower magnetic pull across the grid or tube surface.
- Downstream metal contamination: Ferrous fines or tramp iron start showing up in final product testing or downstream machinery detectors despite the separator being clean.
- Structural casing punctures: Scratches, gouges, or pinhole leaks in the stainless steel jacket expose the internal magnetic circuit to moisture and process fluids.
Regular gauss testing (at least annually) is the most reliable way to catch strength loss before it affects downstream product purity — PML's own range of Gaussmeters and magnetic field meters covers this. If you're seeing any of the signs above, talk to our team about testing or replacing your separator.
