OSENC Magnetic Separation
Control the Test Piece, Gap and Direction
A pull-force value is meaningful only when the complete method is defined. Record the magnetic product, test steel material, size, shape, thickness and surface, contact or gap, pull direction, fixture, instrument, pull rate, temperature, number of repeats and acceptance rule. Two suppliers’ values cannot be compared if any of these conditions differ.
What Pull Force Measures
A pull test measures force in a defined mechanical setup as the test piece is separated from the magnetic product. It can support incoming inspection or comparison of repeat products, but it does not by itself predict capture of irregular moving iron through powder, conveyor burden, air gaps, vibration, moisture or high speed.
Variables That Change the Result
| Variable | Why it matters |
|---|---|
| Test steel | Grade, permeability, saturation and heat treatment affect magnetic response |
| Shape and area | Changes flux path and contact with the pole |
| Thickness | Thin steel may saturate or carry less flux |
| Surface and flatness | Coating, roughness, curvature and debris create microscopic gaps |
| Air gap | Force can fall sharply as separation increases |
| Pull direction | Normal pull and sliding/shear tests are different |
| Fixture and rate | Alignment, compliance, peak capture and motion affect readings |
| Temperature | Changes magnet and sometimes instrument behavior |
Minimum Test Specification
- Part number, drawing, batch, configuration and preconditioning
- Test piece material certificate or controlled specification, dimensions and surface condition
- Exact contact position and orientation on the magnetic product
- Defined zero gap or calibrated spacer thickness
- Force gauge or load cell identity, range and calibration
- Fixture, alignment, pull direction, speed and data capture method
- Temperature, number of repeats, reset method and rest time if relevant
- Statistic, tolerance, pass/fail and treatment of outliers
Basic Test Sequence
- Inspect and clean the magnetic surface and test piece.
- Stabilize the parts at the specified temperature.
- Install the product and test piece in the approved fixture.
- Apply contact, gap or seating force consistently without impact.
- Pull in the stated direction and rate while recording the defined force value.
- Reset the setup and repeat at the same location or defined grid.
- Record raw values, observations, variation and pass/fail.
Pull Force per Area Needs Care
Dividing force by nominal area does not automatically create a transferable material property. Edge leakage, pole coverage, steel saturation, nonuniform contact and fixture geometry remain. Report the original force, original test piece and method alongside any calculated value.
Tube and Grate Tests
A round tube contacts a flat test piece along limited geometry, so ball, washer, plate or specially shaped test methods can produce very different results. Specify axial location, pole location and whether any outer sleeve is installed. Do not compare an exposed magnetic core with a complete easy-clean tube.
Suspended-Magnet Tests
A face pull or lifting test needs a stated target shape, mass or force method, plate thickness, working gap and orientation. It is not equivalent to lifting a bolt buried under a moving burden. Where process protection matters, combine controlled magnetic acceptance with a safe representative conveyor test.
Safety
Strong attraction can pinch fingers, launch steel, damage gauges and overload fixtures. Use guarding, remote handling where appropriate, rated fixtures, controlled tools and the site risk assessment. Personnel should never improvise a lifting demonstration under a suspended load.
Report Requirements
Include product/test-piece identity, photographs or drawing, instrument and calibration, fixture, method, gap, direction, rate, temperature, raw repeats, calculations, tolerance, result, deviations, operator, reviewer and date.
Define the Pull Test Before Comparing Numbers
| Decision rule | Specify target piece, mating plate, contact or spacer, pull direction, fixture alignment and separation speed because each changes the result. |
|---|---|
| Inputs to confirm | Magnet or assembly identity, target material and finish, geometry, gap, temperature, load cell and calibration, fixture, speed, repetitions and acceptance statistic. |
| Risk or limitation | Handheld spring-scale tests with uncontrolled peeling, rocking or contact are not comparable to an axial rigid-fixture result. |
| Buyer action | Approve a photograph or drawing of the setup and report every individual result, not only the highest pull. |
What We Need to Configure This Project
Input set for How to Define a Repeatable Magnetic Pull Force Test
- How we use your data: We compare your material, contamination risk, production target and line interface before we configure a proposal or rule out an unsuitable option.
- Material: name and composition; dry or wet; powder, granule, lump, fibre or slurry; minimum, maximum and typical particle distribution; moisture, stickiness, tendency to cake or bridge, abrasiveness, corrosiveness, bulk density, normal temperature and maximum temperature.
- Production and target: normal and peak throughput, continuous or batch feed, feed uniformity, contaminant or recovery target, magnetic response if known, typical and maximum target size, initial concentration, acceptable residual and whether product loss is permitted.
- Installation: belt width and speed, normal and maximum burden depth, magnet position and rated working distance, available suspension and maintenance space, support and lifting arrangement; cleaning method, permitted shutdown, contact-material, wear and corrosion requirements; indoor, outdoor, washdown, high-humidity, dusty or hazardous-area conditions.
- Supporting project files: drive voltage, frequency and phase where a self-cleaning unit is considered; control interface and any site air requirement; destination country; current drawings, site photographs, running video and a representative material/contaminant sample when testing is needed.
- What you receive next: We use the confirmed inputs to prepare a project-specific drawing and inspection plan. We do not treat performance as confirmed until the agreed design and any required representative test or site acceptance establish the result.
How We Define the Deliverable for Your Project
How to Define a Repeatable Magnetic Pull Force Test: seller-side application review
- Your acceptance risk: A test, spare part or shipment can fail its purpose when the model, method, interface, package or acceptance condition is not defined before the order.
- What we review: We confirm your material or equipment identity, drawing, target result, test position, instrument or part reference, environment, destination and required records.
- What we coordinate: We match the agreed inspection, manufacturing-partner or logistics resource to the scope and keep assumptions separate from verified results.
- Buyer value: This helps you avoid unusable reports, incompatible replacement parts, transport damage, repeated testing and delivery delays.
- Boundary: We do not present a laboratory example, generic part description or packaging concept as evidence for an unverified model or production result.
- Next step: Send the material and target, particle range, moisture, temperature, throughput, contamination, installation drawing, available space, cleaning preference and any sample or site video. Send the test or delivery requirement
Project Support
Need documents, testing support or after-sales help?
Send your order reference, product details, application condition, requested document and supporting photos or videos so we can route the request correctly.
Frequently Asked Questions
What Pull Force Measures?
A pull test measures force in a defined mechanical setup as the test piece is separated from the magnetic product.
Why is “Pull Force per Area Needs Care” important for this decision?
Dividing force by nominal area does not automatically create a transferable material property. Edge leakage, pole coverage, steel saturation, nonuniform contact and fixture geometry remain.
Why is “Tube and Grate Tests” important for this decision?
A round tube contacts a flat test piece along limited geometry, so ball, washer, plate or specially shaped test methods can produce very different results.
Ben — OSENC
Ben has more than 20 years of experience in the magnetic separation equipment industry and has worked with OSENC since 2019. He focuses on magnetic separators, tramp iron removal systems, metal recovery equipment, and custom magnetic separation solutions.
He helps customers clarify material type, particle size, moisture level, capacity, feeding method, target metal, and installation conditions, reducing wrong model selection, failed separation results, and unnecessary sample testing.