So you’re wondering what are shuttering magnets?
Here’s the deal:
What Are Shuttering Magnets?
Shuttering magnets (also called precast concrete magnets) are powerful magnetic tools that secure formwork to steel casting beds during concrete production. Think of them as super-strong magnetic clamps that hold your molds in place while concrete sets.
Pretty simple, right?
But here’s where it gets interesting.
These specialized magnets pack serious holding power – we’re talking 600kg to over 3,000kg of force. That’s like magnetically attaching a small car to your casting bed.
In this guide, as a professional shuttering magnet manufacturer, I’ll show you exactly how shuttering magnets work, why they’re revolutionizing precast concrete production, and how to choose the right ones for your project.
Let’s dive in.
How Shuttering Magnets Actually Work
Here’s something that blew my mind when I first learned it:
Shuttering magnets use neodymium arrays (the strongest permanent magnets on Earth) housed in steel casings to create concentrated magnetic fields.
But how do they actually work?
It’s surprisingly clever.
The On/Off Mechanism
First, the magnet sits on your steel casting bed in the “off” position. The magnetic field stays contained within the housing.
Then you activate it (usually with a button or lever). This drops the magnetic array down, creating direct contact with the steel surface.
BOOM. Instant holding force.
Want to remove it? Just use a lever to increase the air gap between the magnet and the steel. The magnetic attraction drops dramatically, and you can easily reposition or remove the magnet.
Here’s what makes this so powerful:
The steel housing directs ALL the magnetic force downward. None of it gets wasted. Every bit of magnetic energy focuses on holding your formwork in place.
The Science Behind the Hold
The holding force depends on three critical factors:
Surface contact quality – Even tiny air gaps can slash your holding force by 50% or more. That’s why surface smoothness matters big time.
Steel thickness – Thinner steel plates can’t fully utilize the magnet’s power. Most shuttering magnets need at least 10mm thick steel for maximum performance.
Temperature – Standard neodymium magnets start losing strength above 80°C. Keep this in mind during summer operations or if you’re working with heated concrete.
Types of Shuttering Magnets (And When to Use Each)
Not all shuttering magnets are created equal.
After analyzing dozens of precast operations, I’ve found these are the most common types you’ll encounter:
1. Standard Box Magnets
These are your workhorses. Rectangular steel boxes with push-button activation.
Holding force: 600kg – 2,100kg
Best for: Standard wall panels, basic formwork setups
2. Heavy-Duty Magnets
When you need serious holding power, these deliver.
Holding force: 2,100kg – 3,000kg+
Best for: Massive wall elements, high-vibration applications
3. Corner Magnets
Specially designed for 90-degree angles. They maintain precise corners without gaps.
Best for: Columns, beams, architectural elements requiring sharp edges
4. Bar Magnets
Long, continuous magnetic force along straight edges.
Best for: Long wall sections, continuous formwork lines
5. Circular Magnets
Perfect for curved concrete elements.
Best for: Pipes, columns, architectural curves
Pro tip: Match your magnet type to your specific application. Using corner magnets for straight walls is like using a screwdriver to hammer nails – it’ll work, but you’re making life harder than necessary.
Why Shuttering Magnets Beat Traditional Methods
Let me paint you a picture.
Traditional formwork fixing involves:
- Drilling holes in your casting bed (permanent damage)
- Welding fixtures (time-consuming and messy)
- Bolting systems (slow setup and removal)
Now compare that to shuttering magnets:
Setup time: 30 seconds vs. 10+ minutes per fixing point
Surface damage: Zero vs. permanent holes/marks
Reusability: Unlimited vs. single-use consumables
Flexibility: Instant repositioning vs. fixed positions
The math is simple. If you’re setting up 50 fixing points per casting bed, shuttering magnets save you over 8 hours of labor per bed.
That adds up FAST.
Key Benefits That Actually Matter
Here’s what makes shuttering magnets a game-changer:
1. Labor Cost Reduction
One operator can position magnets 10x faster than traditional methods. I’ve seen companies cut formwork setup labor by 70%.
2. Precision Positioning
Need to move a form 5mm? No problem. Try doing that with welded fixtures.
3. Zero Casting Bed Damage
Your steel tables stay pristine. No drill holes. No weld marks. This extends bed life by years.
4. Improved Safety
No hot welding work. No drill bits breaking. No heavy clamps to drop. Just clean, simple magnetic attachment.
5. Consistent Quality
Magnets maintain exact positioning throughout concrete pouring and vibration. Your tolerances stay tight.
Real-World Applications
Shuttering magnets excel in these scenarios:
Wall Panel Production: Both single and double-wall elements. Magnets handle standard panels up to massive architectural pieces.
Beam and Column Manufacturing: Precise edge positioning for structural elements. Corner magnets ensure perfect 90-degree angles.
Custom Architectural Elements: Complex shapes? No problem. Combine different magnet types for unlimited flexibility.
Floor Slab Production: Long bar magnets create continuous edge forms for large slabs.
Infrastructure Components: Pipes, manholes, barriers – if it’s precast on a steel bed, magnets can secure it.
How to Choose the Right Shuttering Magnets
Selecting shuttering magnets isn’t rocket science, but you need to consider these factors:
1. Calculate Required Holding Force
Basic formula: Formwork weight × 3 = Minimum holding force needed
Why 3x? Safety factor for vibration and concrete pressure.
2. Check Your Steel Table Thickness
Most magnets need 10-20mm steel thickness for rated holding force. Thinner steel = reduced performance.
3. Consider Temperature Conditions
Standard magnets: Good up to 80°C
High-temp versions: Handle up to 150°C (but cost more)
4. Assess Formwork Compatibility
Make sure mounting holes align. Standard threads are M12 or M16.
5. Think About Quantity
More magnets = better force distribution. Don’t try to save money by using fewer, stronger magnets. You’ll get better results with proper spacing.
Installation Best Practices
Want maximum performance from your shuttering magnets? Follow these rules:
Clean the surface: Any debris between magnet and steel kills holding force. Even concrete dust matters.
Check flatness: Warped steel reduces contact area. Use a straight edge to verify.
Proper spacing: Place magnets every 300-500mm for standard applications. Heavy-duty needs closer spacing.
Activate fully: Half-engaged magnets = half the holding force. Make sure that lever clicks into position.
Temperature monitoring: In summer, steel beds can exceed 80°C. Check with an IR thermometer if concerned.
Maintenance That Actually Matters
Here’s the thing about shuttering magnets:
They’re incredibly durable IF you maintain them properly.
Critical maintenance tasks:
Daily: Wipe magnetic surface clean. Remove ALL concrete residue.
Weekly: Check activation mechanisms. A drop of oil keeps levers smooth.
Monthly: Inspect for cracks or damage. Test holding force with a pull gauge.
Annually: Professional inspection of magnetic strength. Magnets can lose 1-2% strength per year.
Skip maintenance? Expect problems. I’ve seen neglected magnets drop from 2,000kg to 500kg holding force just from concrete buildup.
Common Mistakes to Avoid
After watching hundreds of precast operations, these mistakes pop up constantly:
Using magnets on painted steel: Paint creates an air gap. Holding force plummets.
Ignoring weight distribution: Concentrating weight on few magnets instead of spreading the load.
Mixing magnet types: Different heights create uneven formwork support.
Exceeding temperature limits: “It’s only 90°C, what could go wrong?” Permanent demagnetization, that’s what.
Skipping cleaning: “A little concrete dust won’t hurt.” Famous last words before formwork shifts mid-pour.
ROI and Cost Considerations
Let’s talk money.
Shuttering magnets aren’t cheap. Expect $200-1,000 per magnet depending on size and strength.
But here’s the payback math:
- Labor savings: 70% reduction in setup time
- Material savings: No consumables (bolts, welding rods)
- Bed preservation: Extends steel table life by 3-5 years
- Quality improvements: Fewer rejects from shifted formwork
Most operations see full ROI within 6-12 months. After that? Pure profit.
Future Trends in Magnetic Formwork
The industry’s evolving fast. Here’s what’s coming:
Smart magnets: Built-in force sensors and wireless monitoring. Know exactly when a magnet needs attention.
Automated systems: Robotic magnet placement for fully automated precast lines.
Stronger materials: New magnetic alloys promise 20% more force in the same size package.
Integrated systems: Magnets designed as part of complete formwork solutions, not add-ons.
Making the Switch
Ready to upgrade from traditional formwork methods?
Start small. Get a set of magnets for one casting bed. Test them on your most common products. Measure the time savings and quality improvements.
Then scale up.
Most companies that try shuttering magnets never go back to drilling and welding. The benefits are too significant to ignore.
Conclusion
So what are shuttering magnets?
They’re the future of efficient precast concrete production. Powerful neodymium magnetic systems that secure formwork instantly, precisely, and without damaging your equipment.
Whether you’re producing simple wall panels or complex architectural elements, shuttering magnets deliver faster setup, better quality, and significant cost savings.
The technology’s proven. The ROI’s clear. The only question is: when will you make the switch?
