Specifications
Product Comparison
Adhesion measured on 3 mm thick low-carbon steel (AISI 1018). All specifications assume off-board driver electronics — weights listed are for the EPM module only. Coated spec assumes 500 µm paint/coating. All values typical.
| Model | Weight | L×W×H (mm) | Bare Steel | 500µm Coat | Ratio | State Switch | Switch | Datasheet |
|---|---|---|---|---|---|---|---|---|
| EPM-100 | 100 g | 60×14×27 | 32 kgf | 18 kgf | 320:1 | 0.8 ±0.3 J | <3 ms | — |
| EPM-150 | 150 g | 80×15×29 | 50 kgf | 29 kgf | 333:1 | 1.2 ±0.5 J | <3 ms | — |
| EPM-250 ★ | 250 g | 108×17×32 | 120 kgf | 65 kgf | 480:1 | 2.0 ±0.8 J | <5 ms | |
| EPM-400 | 400 g | 144×19×35 | 165 kgf | 92 kgf | 413:1 | 3.5 ±1.4 J | <5 ms | — |
| EPM-700 | 700 g | 200×21×39 | 260 kgf | 145 kgf | 371:1 | 5.8 ±2.3 J | <8 ms | — |
| EPM-1000 | 1,000 g | 248×22×42 | 380 kgf | 210 kgf | 380:1 | 9.2 ±3.7 J | <10 ms | — |
Important Notes on These Specifications
These specifications represent products we have designed and produced for customers. They are measured under idealized test conditions: infinitely thick low-carbon steel substrate, precision-ground contact surfaces, and zero air gap. Real-world performance depends on your specific application. Factors such as potting or encapsulation, high-friction interface pads, ferromagnetic interface plates, substrate thickness, surface coatings, temperature, and mechanical tolerances will all affect the achieved adhesion force. We design and optimize EPMs for your explicit requirements and operating conditions — these standard specs are a starting point, not a guarantee for your use case. Contact us to discuss your application.
Scaling Physics
Why Ratio Decreases with Size
As EPMs increase in size, the magnet volume grows cubically while the contact surface area grows only quadratically. Larger magnets also have longer flux paths with more leakage. The result is a natural decrease in adhesion-to-weight ratio at larger scales — from a peak of 480:1 at 250 g down to 380:1 at 1 kg. This is a fundamental magnetic scaling effect, not a design limitation.
Beyond 1 kg
EPM Arrays for Higher Forces
For holding forces that exceed what a single 1 kg EPM module can deliver, we design custom arrays of EPM modules. Arrays allow independent zone control, graduated force application, and fault tolerance — if one module fails, the others continue holding.
Arraying standard EPM modules is the fastest path to high holding force over a large area. Spreading multiple 250 g modules evenly across a steel surface is simpler and more cost-effective than designing a single large EPM — and maintains a much lower profile.
Distributed or compliant EPM arrays can grip non-flat objects: pipes, curved hull sections, rolled steel, I-beams, and irregularly shaped castings. Each module independently conforms to the local surface geometry.
Even applications requiring only a few hundred grams of total EPM mass benefit from array configurations — the distributed contact points improve grip uniformity and provide redundancy.
Array configurations are common in industrial lifting (multi-ton capacity), large-area CNC workholding, and multi-zone robotic grippers. We handle the magnetic circuit optimization, mechanical packaging, and multi-channel driver electronics as a complete system.
Contact us to discuss your force requirements and we'll recommend the right configuration.
Array Advantages
- Scalable to multi-ton holding forces
- Independent zone control for complex geometries
- Redundancy — no single point of failure
- Graduated force application (partial activation)
- Modular maintenance — replace individual units
Common Array Applications
- Heavy steel plate and beam lifting
- Large-format CNC workholding chucks
- Multi-zone robotic grippers
- Mold and die clamping systems
- Ship hull and tank inspection robot platforms
Customization
Every Specification is Adjustable
Every parameter — dimensions, force, weight, switching speed, coil resistance, and driver protocol — can be customized. We routinely modify these designs for specific substrates, form factors, temperature ranges, and integration constraints.
Custom Geometry
Need a round EPM, a flat bar shape, or something that fits a specific cavity? We design the magnetic circuit around your mechanical constraints.
Optimized for Your Substrate
Standard specs assume ideal steel. If you're gripping painted, galvanized, coated, or thin-gauge material, we optimize the circuit for your real-world surface.
Matched Driver Electronics
Each EPM comes with (or can be paired with) a custom driver board matched to the coil, your power budget, and your communication protocol.
Custom Is Our Standard
90% of the EPMs we produce are custom-tailored to the application. Tell us your force requirements, weight budget, and operating conditions — we'll design the right solution.
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