B2B Buyers Need to Know About Disk Neodymium Magnets
Publish Time: 2025-02-20 Origin: Site
If you're in the business of sourcing high-performance magnets, You must have some understanding of disk Neodymium magnets —also known as disc or round neodymium magnets. These little magnets are a good solution for countless industrial applications, but there are significant differences between various types of magnets.. As a manufacturer with 20+ years of experience in magnet field, let me explain what really matters, straight from a magnet maker's perspective.
1. The Nitty-Gritty: Technical Specs That Actually Matter
When you're buying magnets for industrial use, you need hard data. Here's what you should be looking at:
1.1 Size and Tolerances
Disk neodymium magnets come in a wide range of sizes, from tiny 10mm diameter pieces to hefty 180mm ones(like a button to a dinner plate). Magnetic thickness typically between 3mm and 120mm. But here's the kicker: tolerances matter. For high precision applications, thickness tolerances should be ±0.03mm. For general industrial use, tolerances ±0.15mm is usually fine.
Pro Tip: Be sure to double-check the specs with your supplier. The mismatch can lead to insufficient magnetic force, difficulties in assembly, and even additional costs associated with repurchase.
1.2 Disk Neodymium Magnetic Performance
Not all magnets are equal. There are quite differents in Remanence/Coercivity/Max Operating Temp. The composition content and processing technology of neodymium magnet determines its strength and performance. Here's a common parameters:
Grade | Remanence (Br) | Coercivity (HcB) | Max Operating Temp |
11.7-12.2 kG | ≥10.9 kOe | 80°C | |
14.3-14.8 kG | ≥10 kOe | 60°C | |
50M | 14-14.5 kG | ≥13 kOe | 100°C |
45H | 13-13.6 kG | ≥12.1 kOe | 120°C |
35SH | 11.7-12.2 kG | ≥11 kOe | 150°C |
33AH | 11.3-11.7 kG | ≥10.6 kOe | 230°C |
Fun Fact: An N52 magnet disc is about 40% stronger than an N35, but High-strength magnets are more susceptible to damage from external forces or impacts compared to low-strength magnets.. So, if your application involves high impact, you might want to stick with low-strength magnets.
1.3 Neodymium Magnets Coatings and Corrosion Resistance
Neodymium magnet is not perfect. Although the magnetic force is strong, but also it is easy to rust. That's why coatings are crucial for neodymium magnet. The most common options are:
- Nickel (Ni-Cu-Ni) coating: Great for indoor use.
- Epoxy coating: Better for harsh environments.
- Zinc coating: For niche applications where non-magnetic surfaces are a must.
Coating Types | Color | Thickness(μm) | SST Testing (H) | PCT(H) | Humidity and Heat | Applied | Characteristics |
NiCuNi(Rolling) | Silver | 10~25 | ≥24 | ≥48 | 500 | ≤200 | Good Hardness |
NiCuNi(Hanging) | Silver | 10~25 | ≥24 | ≥48 | 500 | ≤200 | |
Black NiCuNi | Gun | 12~25 | ≥48 | ≥48 | 500 | ≤200 | Nice Appearance |
Ni+CR | Dark Silver | 12~20 | ≥48 | ≥48 | 500 | ≤200 | Excellent Hardness |
Ni+AU | Gold | 12~20 | ≥48 | ≥48 | 500 | ≤160 | Good Conduction |
Ni+AG | Silver | 12~20 | ≥48 | ≥48 | 500 | ≤160 | Good Conduction |
ZN CR3+ | Blue | 5~10 | ≥15 | / | 48 | ≤70 | Common Anti-corrosion |
Black/Grey Epoxy | Black/Grey | 12~25 | Black Epoxy≥72 | ≥72 | 120 | ≤130 | Excellent Anti-corrosion |
Teflon | Black/Grey | 8~15 | ≥24 | ≥48 | 120 | ≤260 | High Temperature |
2. Real-World Applications: Where Disk Neodymium Magnets Shine
Different industries have different needs. Here's how disk magnets are used in the real world:
2.1 Disk Neodymium Magnets For Speaker Industry
In sound equipment, disk neodymium magnets are a necessary part. Help turn electrical signals into sound. The size of the speaker determines the size of the neodymium magnets
2.2 Disc Neodymium Magnets For Magnetic Toys
Lots of disc neodymium magnets are used in magnetic toy market. Like building blocks, fishing toys,car toys etc. It helps kids learn basic physics. Hape, a famous toy company, used disc neodymium magnets in its toys
Key Requirement: For the toy industry, it’s very important that products meet safety standards like ASTM and EN71.
2.3 Disc Neodymium Magnets Decorating Industry
Disk neodymium magnets are also used heavily in the decorating industry, especially refrigerator magnets. Magnets are needed for refrigerator magnets of all shapes and patterns.
3. What are the factors that affect the Price of Disk Neodymium Magnets?
Let’s talk about price, which concerns you the most. Why does the price of disk neodymium magnets vary so much between suppliers?
3.1 Material Costs
Rare earth metals aren't cheap. As of Q1 2025, The price of N35 neodymium iron boron (NdFeB) magnet blanks is $18/kg. If you need high-temperature grades, adding Dysprosium can bump up the cost by 15–20%.
3.2 Processing Costs
Sintered magnets are stronger but cost about 10 times more than bonded magnets. However, bonded magnets are easier to machine, which can save you money on secondary processing.
3.3 Order Volume
Like most things, bulk purchasing will give you greater leverage with suppliers.
4. Quality Assurance: What to Look For in purchase neodymium magnets？
When you're sourcing neodymium magnets, quality is the most important. Here's what you should be asking for:
- Material Traceability: Mill test reports with batch numbers.
- Testing Certificates: Magnetic flux distribution, salt spray test results, and RoHS/REACH compliance.
- Process Certifications: ISO 9001 is good indicators of a reliable supplier.
- B-H Curve Analysis
Demagnetization curves measured via BH tracer (e.g., Magnet-Physik Permagraph), detailing Br (remanence), Hcb (coercivity), and Hcj (intrinsic coercivity). Critical for evaluating thermal stability and anti-demagnetization performance.
-Gauss Value Mapping
Surface flux density uniformity tests using transverse Hall probes (e.g., Lakeshore 475 Gaussmeter), essential for precision applications like BLDC motors or medical sensors.
5. Customization Neodymium Magnets
Sometimes, off-the-shelf just doesn't meet your need. Share your customization needs with the supplier; a good neodymium magnets supplier will provide you with reasonable suggestions and ultimately meet your requirements.:
- Non-Standard Sizes: Need a 37.5mm diameter magnet for a retrofit? No problem.
- Multi-Pole Magnetization: Up to 12 poles for encoder disks.
- Hybrid Assemblies: Disk magnets pre-mounted in aluminum or stainless steel housings.
6. Disk vs. Other Shapes: A Quick Comparison
Feature | Disk Magnets | Block Magnets | Ring Magnets |
Flux Direction | Axial | Through thickness | Radial |
Mounting Simplicity | ★★★★★ | ★★★☆☆ | ★★★★☆ |
Cost Efficiency | High (simple geometry) | Medium | Medium |
7. FAQs for Neodymium Magnets
Q: Can disk neodymium magnets be demagnetized ?
A: Yes, Temperature is the most critical factor affecting the demagnetization of neodymium iron boron (NdFeB) magnets..
Like N series neodymium magnets, the Operating Temperature is 80℃/176°F, If the ambient temperature exceeds this threshold, demagnetization will occur. Once the temperature exceeds the Curie temperature (310°C to 370°C), neodymium iron boron (NdFeB) magnets will completely lose their magnetism.
Magnet Grade | Operating Temp (°C) | Operating Temp (°F) |
N | 80°C | 176°F |
M | 100°C | 212°F |
H | 120°C | 248°F |
SH | 150°C | 302°F |
SH-T | 160°C | 320°F |
UH | 180°C | 356°F |
UH-T | 190°C | 374°F |
EH | 200°C | 392°F |
AH | 220°C | 428°F |
Operating Temperature for different series Neodymium Magnets
Q: What's the lead time for custom disc neodymium magnets?
A: Standard lead time is 4–5 weeks. If there is blank stock, the fastest delivery time is 5-7 days. If you're in a rush, expedited shipping can get it down to 2 weeks.
Q: How do I prevent brittle fractures during installation?
A: Use nylon insertion tools and installation gently avoid impact loads over 20 J/m⊃2;.
8. Why Partner with a Specialized Manufacturer?
Choosing the right supplier can make or break your project. Here's why working with a specialized manufacturer like [bwmagnets] pays off:
- Cost Control: We handle everything in-house, which means we can offer prices 15–20% lower than traders.
- R&D Support: Need a custom solution? Our engineers are here to help.
- Supply Chain Security: We dual-source our rare earth materials to ensure consistent supply.
- Global Logistics Compliance
Express/air freight options with full documentation:
l MSDS (Material Safety Data Sheet) aligned with UN GHS standards.
l Air Transport Certification issued by Shanghai Chemical Research Institute (SCRI) for hazardous material compliance (IATA DGR 64th Edition).
- 100% Automated QC
CCD (Computer Vision Inspection) systems for dimensional accuracy (±0.01mm tolerance) and surface defect detection (cracks, plating voids). Validated by ISO/IEC 17025:2017 calibration.