N42 Neodymium Ring Magnets
Technical Specifications
| Magnetic Property | Value Range |
|---|---|
| Max Energy Product (BH)max | 40 - 42 MGOe (318 - 334 kJ/m³) |
| Remanence Br | 13.0 - 13.5 kGs (1.30 - 1.35 T) |
| Coercivity Hcb | ≥ 11.0 kOe (876 kA/m) |
| Intrinsic Coercivity Hcj | ≥ 12.0 kOe (955 kA/m) |
| Max. Operating Temperature | 80℃ (N grade series) |
| Curie Temperature | 310℃ |
| Temperature Coefficient (Br) | -0.12 %/℃ (20–100℃) |
| Temperature Coefficient (Hcj) | -0.6 %/℃ (20–100℃) |
| Density | 7.5 g/cm³ |
| Hardness | 550 - 650 Vickers |
| Electrical Resistivity | 140 - 160 μΩ·cm |
We sell all grades of neodymium magnets, custom shapes, sizes, and coatings.
Why Choose N42 Grade Magnets?
N42 neodymium ring magnets rank among the most widely used grades for industrial applications. They deliver an ideal balance between magnetic performance and cost, making them the top pick for most non-extreme working conditions.
We sell all grades of neodymium magnets, custom shapes, sizes, and coatings.
Typical Applications
Thanks to outstanding cost efficiency and stable magnetic performance, our N42 neodymium ring magnets are widely adopted across industrial and consumer electronics sectors.
Motor Industry: Stepper motors, BLDC brushless motors, servo motors, micro motors, vibration motors.
Sensors: Hall effect sensors, proximity switches, speed sensors, position sensors, flow sensors.
Magnetic Equipment: Magnetic chucks, magnetic separators, iron removers, magnetic stirrers, magnetic couplings.
Acoustic Devices: Speakers, earphones, receivers, buzzers, ultrasonic sensors.
Consumer Electronics: Smartphones, tablets, smart wearables, wireless chargers, Bluetooth devices.
Medical Equipment: MRI machines, medical pumps, surgical instruments, rehabilitation devices.
N42 vs N35 vs N45 vs N48 vs N52 Comparison
| Magnetic Parameter | N35 | N42★ | N45 | N48 | N52 |
|---|---|---|---|---|---|
| Max Energy Product (MGOe) | 33–36 | 40–42 ★ | 43–46 | 46–49 | 50–53 |
| Remanence (kGs) | 11.7–12.1 | 13.0–13.5 ★ | 13.3–13.7 | 13.5–14.0 | 14.2–14.8 |
| Max Operating Temp (℃) | 80 | 80 | 80 | 80 | 80 |
| Relative Price | Low (1.0x) | Medium (1.15x) ★ | Medium-High (1.3x) | High (1.5x) | Highest (2.0x) |
| Cost-Performance Ratio | Average | Best ★ | Good | Average | Poor |
| Recommended Scenarios | Cost-sensitive, low magnetic demand | Most general industrial applications ★ | Medium-high magnetic requirements | High magnetic performance demand | Extreme ultra-high magnetic performance needs |
Note: The relative price multiples are for reference only; actual prices fluctuate with market raw material conditions. N42 delivers approximately 20% higher magnetic performance with just a 15% price increase, making it the grade with the highest return on investment among all standard neodymium grades.
What Does N42 Grade Mean?
N42 is a standard grade within the neodymium magnet classification system, consisting of a letter prefix and numeric suffix that indicate coercivity class and maximum energy product respectively.
Letter N: Stands for the standard N-series magnet. It features intrinsic coercivity Hcj ≥ 12 kOe with a maximum continuous operating temperature of 80°C.
Number 42: Represents the rated maximum energy product (BH)max of roughly 42 MGOe (Mega-Gauss-Oersteds).
Extended temperature grades: For higher heat resistance, upgraded variants include M (100°C), H (120°C), SH (150°C), UH (180°C), and EH (200°C).
Performance tolerance range: Magnetic properties slightly fluctuate within the same grade; N42 neodymium magnets deliver a (BH)max range of 40–42 MGOe.
Fullzen N42 Magnet Manufacturing Capabilities
At Fullzen Technology, we operate 12 dedicated production lines exclusively for N42 grade ring magnets. We maintain full independent control over the entire workflow from raw material batching, vacuum sintering to finished precision machining, with a monthly output of 20 tons to fulfill mass orders and custom requests from all clients.
Large Production Capacity: 12 vacuum sintering furnaces support 20 tons of N42 magnets monthly, with over 50 standard sizes kept in stock.
Ultra-High Precision Machining: Advanced internal & external cylindrical grinders deliver tight dimensional tolerance down to ±0.02 mm and concentricity within ≤0.03 mm.
Diversified Magnetization Options: Axial magnetization, radially magnetized, multi-pole (2–120 poles), skew magnetization and Halbach array magnetization available.
Comprehensive Surface Coatings: More than 10 coating solutions including NiCuNi, zinc, epoxy, phosphating, Parylene, gold, silver and electrophoretic paint.
Strict Full-Scale QC Inspection: 100% inspection on magnetic flux, dimensions and surface appearance; magnetic performance deviation between batches is controlled within ±2%.
Flexible Custom Machining: Secondary processing services are available for special profiles, stepped rings, chamfers, slots, countersunk holes and other customized structures.
Custom N42 Ring Magnet Solutions
Standard off-the-shelf sizes often fail to match unique application requirements, so Fullzen delivers flexible customization covering dimensions, geometries, surface coatings and magnetization patterns.
Custom Dimensions: Custom OD ranging from 2 mm to 200 mm, wall thickness over 0.5 mm, height from 0.5 mm to 100 mm
Special Shapes: Stepped rings, tapered rings, D-shaped rings, slotted rings, countersunk hole rings and other irregular profiles
Custom Coatings: Environment-matched coating options — epoxy for marine humid conditions, gold plating for medical-grade applications
Custom Magnetization: Custom pole layouts, unequal pole arcs, sine-wave magnetization and other bespoke magnetic designs
Pre-Assembled Magnet Components: Integrated assemblies paired with metal or plastic parts to cut your in-house assembly workload
High-Temperature Grade Upgrade: Swap standard N42 for heat-resistant N42M (100℃) or N42H (120℃) if higher working temperature is required
Sample Program
Fullzen offers sample testing services for N42 neodymium ring magnets. In-stock sizes can be shipped quickly, while custom prototypes are available to help you verify magnetic performance and assembly compatibility before mass production.
Standard Stock Samples: Over 50 ready sizes in inventory, deliverable within 1–3 days with a modest sample fee.
Custom Prototypes: Manufactured strictly per your drawings, lead time of 7–15 days; tooling fees depend on dimension complexity.
Minimum Sample Quantity: 10–50 pieces for standard items, 5–20 pieces for custom designs (subject to magnet size).
Full Test Documentation: Material certificates, dimensional inspection reports and magnetic performance test reports supplied with every sample batch.
Sample Fee Rebate: The upfront sample cost will be fully refunded once your bulk order reaches the equivalent of $5,000 order value.
Quality Assurance & Certifications
Stable performance of N42 neodymium ring magnets directly determines the quality of your end products. Fullzen has built a rigorous full-process quality control system to guarantee every magnet meets standardized specifications.
Raw Material Inspection: Every batch of rare earth raw materials is tested for chemical composition and impurity content to maintain consistent raw material quality.
In-Process Control: Real-time monitoring of sintering curves; test samples from each furnace batch are analyzed for BH curves and magnetic properties.
100% Finished Goods Inspection: Full inspection on dimensions, magnetic flux and surface appearance; zero defective products shipped out.
Authorized Certifications: ISO9001:2015, IATF16949, RoHS and REACH compliance certifications.
Reliability Testing: Salt spray test, thermal cycling, high-temperature aging, vibration shock and tensile pull tests.
Why Choose Fullzen for N42 Ring Magnets?
N42 ranks among the most widely used neodymium magnet grades, making it critical to partner with a dependable manufacturer. Thanks to consistent quality, competitive pricing and fast lead times, Fullzen has become the top supplier of N42 ring magnets for over 300 clients worldwide.
Frequently Asked Questions
Fullzen has compiled common questions about N42 ring magnet grade selection and real-world applications to help you quickly grasp product properties. Feel free to reach out to our sales engineers for further technical support.
With identical dimensions, N42 delivers roughly 20% higher max energy product and 11% higher remanence than N35. Actual pull force or magnetic field gain varies based on magnetic circuit design and air gap, normally ranging from 10% to 20%.
Selection guidance: Stick with N35 if it meets your magnetic demands to cut costs. If N35 lacks sufficient power or your design space is limited, N42 offers the best cost-performance upgrade. Pick higher grades only when ultra-small size & light weight are mandatory. Fullzen provides free magnetic circuit simulation to confirm your optimal grade.
80°C is the rated maximum continuous operating temperature for N42 grade. Below this threshold, reversible magnetic loss stays under 5% and full magnetism recovers after cooling down. Short exposure to 90–100°C causes slight irreversible demagnetization (≤2%) and rarely leads to complete failure. Long-term operation above 80°C triggers gradual magnetic decay and shortens service life.
For high-temperature working environments, select heat-resistant variants with equivalent magnetic performance: N42M (100°C), N42H (120°C), N42SH (150°C), etc.
1. NiCuNi (Nickel-Copper-Nickel): Most widely used, bright finish, wear-resistant, 24–72 hours salt spray resistance for general indoor applications.
2. Zinc plating: Budget-friendly option with 12–48 hours salt spray resistance for cost-sensitive projects.
3. Epoxy coating: Superior anti-corrosion performance with 100–1000 hours salt spray resistance, ideal for humid & outdoor environments.
4. Parylene (Teflon): Ultra-thin uniform film with strong chemical resistance, suitable for medical and precision equipment.
5. Gold / Silver plating: Excellent electrical conductivity for electric contact applications.
Base your coating choice on environmental corrosiveness, appearance requirements and budget. Fullzen technical team can recommend the most suitable coating solution for your use case.
We offer multiple magnetization patterns for N42 ring magnets:
1. Axial magnetization: Top and bottom faces serve as N & S poles, the most standard magnetization method.
2. Radial magnetization: Inner and outer cylindrical surfaces form opposite poles, widely adopted in motors and sensors.
3. Multi-pole magnetization: Multiple poles evenly distributed around the circumference (4P, 8P, 12P, 24P, 48P common), mainly used for motors and encoders.
4. Skew magnetization: Poles angled relative to the central axis for special motor designs.
Magnetization directions and pole counts are fully customizable. Fullzen provides professional magnetization layout suggestions based on your magnetic circuit design and custom magnetization fixtures upon request.
Tolerance ranges differ by machining process:
- Standard grinding: ±0.05 mm ~ ±0.1 mm
- Precision fine grinding: ±0.02 mm ~ ±0.05 mm
- Ultra-precision lapping: ±0.01 mm
Tighter tolerance drives up manufacturing costs and extends lead time. Select tolerance grades matching your actual assembly requirements to avoid over-engineering and unnecessary expenditure. Our engineers will recommend the most cost-effective tolerance standard to satisfy assembly demands while controlling your budget.
Fullzen implements flexible MOQ policies: Stock standard samples: 1 piece minimum for testing validation Custom prototype initial orders: 100–500 pieces, negotiable down to 50 pieces for long-term cooperative clients We understand small-batch verification demands during product development, so we offer dedicated low-volume prototyping to complete testing without heavy inventory pressure. Unit prices drop significantly with larger order volumes.
Under ideal working conditions (temperature below rated limit, no strong reverse magnetic fields, no corrosion), neodymium permanent magnets experience extremely slow natural decay under 1% per year, with a service life of 10–20+ years.
These scenarios accelerate demagnetization:
1. Continuous operation exceeding maximum rated temperature
2. Exposure to strong opposing magnetic fields
3. Corrosion damaging internal magnet microstructure
4. Severe impact or vibration (NdFeB is brittle, cracking weakens magnetic performance)
We recommend reserving a 10–15% magnetic performance margin during design and applying proper protective coatings for long-term reliability.
Wall thickness is restricted by machining feasibility, and ultra-thin walls carry high production difficulty. A wall-to-outer-diameter ratio above 1:10 delivers stable yields:
- OD below 20 mm micro rings: Minimum wall thickness 0.5 mm
- OD 20–50 mm medium rings: Recommended wall thickness ≥1 mm
- OD over 50 mm large rings: Recommended wall thickness ≥2 mm
Thin-wall rings have lower production yield and higher unit cost. Contact our technical team in advance to assess manufacturability and cost impact if ultra-thin walls are required in your design.
Related Ring Magnet Products
Explore more neodymium ring magnet options from Fullzen to locate the optimal solution matching your application requirements.
Neodymium Ring Magnets: Complete catalog guide covering all grades, sizes and magnetization styles
N52 Neodymium Ring Magnets: Highest mass-produced energy grade with 52 MGOe, ideal for miniaturized designs
Large Neodymium Ring Magnets: Custom oversized rings with OD over 200 mm for wind power and MRI equipment
Radially Magnetized Ring Magnets: Inner & outer cylindrical poles, widely used in motors and sensors
Countersunk Ring Magnets: Pre-drilled countersunk holes for easy screw mounting in structural assemblies
Request Your Free Quote Toda
Share your detailed specifications and application requirements for N42 ring magnets, and our Fullzen technical team will deliver customized professional N42 neodymium ring magnet solutions and quotations within 24 hours.
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