4" x 3" N42 Neodymium Disc Magnets – Heavy-Duty Industrial Rare Earth Magnets
Quick Facts
| Attribute |
Value |
| Magnet Type |
Neodymium Rare Earth Disc Magnet |
| Grade |
N42 |
| Shape |
Disc |
| Diameter |
4" (101.6 mm) |
| Thickness |
3" (76.2 mm) |
| Pull Force |
Approximately 1,200 lbs* |
| Material |
NdFeB (Neodymium-Iron-Boron) |
| Coating |
Nickel-Copper-Nickel (Ni-Cu-Ni) Triple Layer |
| Magnetization |
Through Thickness (Axially Magnetized) |
| Br Max |
13,200 Gauss |
| Certification |
ISO Certified |
*Note: Actual pull force may vary depending on the application, contact surface, steel thickness, air gap, and mounting method. This is an extremely powerful industrial magnet and should only be handled using appropriate safety precautions.
Quick Answers
| Question |
Answer |
| How strong is this magnet? |
Approximately 1,200 lbs of pull force under ideal conditions. |
| What is this magnet made of? |
NdFeB (Neodymium-Iron-Boron) rare earth material. |
| Is this stronger than N35 magnets? |
Yes. N42 provides significantly greater magnetic strength than N40, N38, and N35 magnets of the same size. |
| Can it be used outdoors? |
Yes, but additional sealing is recommended for long-term outdoor or marine environments. |
| What is it commonly used for? |
Industrial lifting systems, magnetic separators, manufacturing equipment, heavy-duty fixtures, engineering projects, robotics, and scientific research. |
Product Overview
These 4" x 3" N42 Neodymium Disc Magnets are designed for the most demanding industrial applications where maximum holding power and deep magnetic penetration are essential. The 4-inch diameter provides an exceptionally large contact area, while the massive 3-inch thickness produces an extremely powerful magnetic field capable of generating approximately 1,200 pounds of pull force under ideal conditions. Their size and strength make them suitable for industrial machinery, magnetic lifting systems, heavy-duty fixtures, and specialized engineering applications.
Manufactured from premium N42 grade NdFeB (Neodymium-Iron-Boron), these magnets deliver substantially greater magnetic performance than N40, N38, and N35 grades. They are commonly used in magnetic separators, industrial automation, manufacturing equipment, robotics, heavy-duty tooling, scientific laboratories, and custom engineering projects requiring reliable, high-strength magnetic performance.
Each magnet is protected by a durable Nickel-Copper-Nickel (Ni-Cu-Ni) triple-layer coating, providing outstanding resistance to corrosion, scratches, and chipping while maintaining a smooth, polished finish. Manufactured in ISO-certified facilities, these magnets provide consistent quality and dependable long-term performance even in demanding industrial environments.
What Is a Neodymium Disc Magnet?
A neodymium disc magnet is a permanent NdFeB (Neodymium-Iron-Boron) magnet manufactured from an alloy of neodymium, iron, and boron. Neodymium magnets are the strongest commercially available permanent magnets and are widely used throughout manufacturing, robotics, automation, electric motors, magnetic separation systems, research laboratories, and heavy industrial equipment.
This magnet is magnetized through its 3-inch thickness (axially magnetized), placing the north and south poles on the two flat circular faces. This orientation maximizes holding force against ferromagnetic surfaces while producing a deep magnetic field ideal for industrial applications.
Neodymium magnets are also commonly known as Neo magnets, NdFeB magnets, NIB magnets, or super magnets.
How Strong Is This Magnet?
This 4" x 3" N42 disc magnet delivers approximately 1,200 pounds of pull force under ideal laboratory conditions using a thick, clean steel plate.
Actual holding force depends on several factors, including:
- Surface material
- Steel thickness
- Contact area
- Air gap
- Mounting method
- Environmental conditions
Due to its exceptional magnetic strength, this magnet should only be handled using proper safety procedures. Keep it away from electronic devices, magnetic storage media, watches, medical implants, and loose ferrous objects.
Note: Pull force values are measured under ideal laboratory conditions. Actual performance should always be verified for your specific application.
Technical Specifications
| Specification |
Value |
| Magnet Type |
Neodymium Rare Earth Disc Magnet |
| Grade |
N42 |
| Shape |
Disc |
| Diameter |
4" (101.6 mm) |
| Thickness |
3" (76.2 mm) |
| Pull Force |
Approximately 1,200 lbs* |
| Material |
NdFeB (Neodymium-Iron-Boron) |
| Coating |
Nickel-Copper-Nickel Triple Layer |
| Magnetization |
Through Thickness (Axially Magnetized) |
| Br Max |
13,200 Gauss |
| Certification |
ISO Certified |
Magnet Grade Comparison
| Grade |
Relative Strength |
Typical Applications |
| N35 |
Standard |
General purpose |
| N38 |
Moderate |
Consumer products |
| N40 |
High |
Industrial |
| N42 |
Higher |
Engineering & industrial equipment |
| N52 |
Maximum |
Maximum-performance applications |
Disc Magnet Size Comparison
| Size |
Typical Use |
| Small |
Crafts & sensors |
| Medium |
General holding |
| Large |
Industrial mounting |
| Extra Large (4" × 3") |
Heavy industrial lifting, magnetic separation, machinery, and engineering systems |
Applications by Industry
| Industry |
Common Uses |
| Manufacturing |
Heavy-duty fixtures, jigs & tooling |
| Industrial |
Magnetic lifting systems & separators |
| Robotics |
Large positioning systems |
| Engineering |
Specialized equipment & prototypes |
| Scientific |
Laboratory research & testing |
| Mining & Recycling |
Magnetic separation equipment |
Common Questions About This Magnet
What is the pull force?
This magnet provides approximately 1,200 pounds of pull force under ideal laboratory conditions.
Is N42 stronger than N35 magnets?
Yes. N42 provides substantially greater magnetic strength and holding power than N35 magnets of the same dimensions.
Can it rust?
The Nickel-Copper-Nickel triple-layer coating provides excellent corrosion resistance. If the coating becomes damaged and moisture reaches the magnet, corrosion may eventually occur.
Can it be used outdoors?
Yes. However, additional sealing is recommended for prolonged outdoor exposure, marine environments, or high-humidity conditions.
What direction is it magnetized?
This magnet is magnetized through its 3-inch thickness (axially magnetized), with the north and south poles located on the two flat circular faces.
Do you offer bulk discounts?
Yes. Contact Super Magnet Store for wholesale pricing and volume discounts on OEM, manufacturing, industrial, educational, research, and reseller orders.
Why Buy From Super Magnet Store?
- Premium NdFeB rare earth magnets
- ISO-certified quality
- High-performance N42 magnetic grade
- Durable Nickel-Copper-Nickel triple-layer coating
- Exceptional industrial holding power
- Precision manufacturing
- Excellent corrosion resistance
- Consistent magnetic performance
- Competitive pricing
- Bulk discounts available
- Fast shipping
- Trusted by manufacturers, engineers, industrial professionals, researchers, and OEMs worldwide
