Large Neodymium Ring Magnets

Short Description:

Fullzen Large-Size NdFeB Ring Magnets are manufactured using a directional crystallization sintering process, with a maximum outer diameter of up to 500mm and magnetic performance uniformity deviation ≤ ±3%, meeting the high-performance requirements of industrial applications such as large motors, wind power generation, and magnetic separation equipment.

Large neodymium ring magnets support both integral sintering and segmented assembly process options, allowing customers to choose the optimal structural solution based on specific application scenarios. Produced in an ISO9001/IATF16949 certified facility, single-piece weight can reach over 50kg.

Key Advantages of Large Ring Magnets：

The manufacturing challenge of large-size NdFeB ring magnets lies in stress control and magnetic performance uniformity during large-scale sintering. Fullzen has broken through conventional size limitations with its proprietary processes, providing reliable magnetic source solutions for large equipment manufacturers.

✅Large-Scale Forming Capability: Utilizing isostatic pressing + high-temperature sintering technology, the maximum outer diameter of integral rings can reach 500mm, far exceeding the industry standard of 200mm.

✅Excellent Magnetic Performance Uniformity: Directional crystallization technology ensures magnetic performance deviation across the entire ring ≤ ±3%, effectively preventing local demagnetization and vibration-induced noise.
✅ Flexible Assembly Options: Segmented assembly technology enables ultra-large ring magnets exceeding meter-scale diameters, with magnetic performance close to that of integral rings and more cost-effective solutions.

✅ High Crack Resistance: Through optimized composition formulation and precisely controlled sintering curves, large-size ring magnets exhibit low internal stress and mechanical strength 20% higher than the industry average.

✅Multiple Magnetization Methods: Supports axial magnetization, radial magnetization, multi-pole magnetization, Halbach array, and various other magnetization configurations.

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What Are Large Neodymium Ring Magnets?

Large neodymium ring magnets generally refer to annular permanent magnets with outer diameters over 100mm. Manufacturing difficulty rises exponentially with growing size, so magnetic uniformity, mechanical toughness and dimensional precision act as core indicators to judge a magnet supplier’s technical capacity.

Industry definition: Rings with OD ≥100mm or single weight ≥1kg are classified as large-size neodymium rings.

Core production bottlenecks: Oversized blanks easily crack, deform or suffer ingredient segregation during sintering, sharply lowering finished product yield.

Industry technical trends: Monolithic rings target larger diameters and higher remanence; segmented spliced rings focus on cost reduction and magnetic efficiency optimization.

We sell all grades of neodymium magnets, custom shapes, sizes, and coatings.

Fast Global Shipping: Meet standard air and sea secure packing, More than 10 years of export experience

Customized is Available: Please offer a drawing for your special design

Affordable Price: Choosing the most suitable quality of products means effective cost savings.

Fullzen Large Magnet Manufacturing Capabilities

Fullzen runs 3 large isostatic presses and 6 vacuum sinter furnaces, matched with a dedicated precision machining production line for oversized ring magnets. We handle full in-house production from mold design, blank forming and sintering to precision machining.

Forming capacity: 3 sets of 500-ton isostatic presses, max forming diameter 600mm, single pressing weight up to 80kg

Sinter workshop: 6 vacuum furnaces sized Φ600×800mm for stable mass output, monthly capacity 50 tons of large magnets

Precision machining: Over 20 internal & external grinders, CNC lathes and wire-cut machines with ±0.02mm machining accuracy

Magnetization equipment: Pulse magnetizers with max 50000J energy to fully saturate all types of large ring magnets

Full testing lab: High-precision gauss meters, flux testers, 3D magnetic field scanners and non-destructive crack inspection gear

Splicing technology: Ultra-precise tile splicing with air gap controlled below 0.1mm, nearly matching monolithic magnetic performance

Technical Specifications

Below is our standard size range for large neodymium ring magnets. Extra-large or special-performance requirements can be fully customized with our technical team.

Oversized forming capacity: Combined isostatic pressing and high-temperature sintering produce monolithic rings up to 500mm OD, far exceeding the common industry limit of 200mm.

Excellent magnetic uniformity: Crystal orientation sintering restricts whole-ring flux deviation within ±3%, eliminating partial demagnetization and abnormal vibration noise.

Flexible splicing solution: Segmented tile splicing creates giant rings over 1 meter wide, delivering nearly identical magnetic performance as monolithic rings at lower cost.

High crack resistance: Optimized rare earth formula and staged sinter curves cut internal stress, delivering mechanical strength 20% higher than industry average.

Diverse magnetization modes: We support axial magnetization, radially magnetized ring magnets, multi-pole magnetization and Halbach array layout for special magnetic circuit designs.

Monolithic vs Segmented Ring Magnets

Two mainstream manufacturing methods for large ring magnets have distinct pros and cons in magnetism, cost and durability. You can make a comprehensive selection based on your working conditions.

Custom Large Magnet Solutions

Fullzen runs full in-house production chains for bonded NdFeB ring magnets, covering mold development, molding, magnetization and full performance inspection. All technical links are independently controlled to stabilize delivery and quality.

Compression molding workshop: 6 automatic presses, annual output 120 million pieces, max OD 150mm

Injection molding workshop: 8 injection machines compatible with PA6, PA12, PPS and epoxy binders

Independent mold workshop: Custom molds with service life over 500,000 shots, 7–15 days lead time for new molds

Multi-pole magnetization equipment: 5 pulse magnetizers supporting radial, skewed and Halbach magnetization

Complete testing lab: Gauss meters, fluxmeters, BH curve testers, CMM coordinate measuring machines, high-low temperature cycling chambers

Composite molding technology: Integrate metal shafts, iron sleeves and shielding sleeves into one single magnet component

Sample Program

Fullzen offers sample testing services for large neodymium ring magnets, including standard stock samples and custom prototype processing to verify magnetic performance and assembly compatibility before mass production.

Standard stock samples: Ready Φ100–200mm rings deliverable within 3–5 working days, sample material fees apply.

Custom drawing samples: Processed per your technical drawings, delivered in 15–30 days with tooling fees based on complexity.

Segmented prototype samples: Validate splicing uniformity and mechanical strength, lead time 20–35 days.

Complete test reports: Dimensional inspection data, magnetic flux certificates and material analysis; non-destructive crack testing reports optional.

Sample cost refund policy: Full sample and testing fees refundable when your bulk order reaches 1 ton or above.

Quality Assurance & Certifications

Large neodymium ring magnets are core components of critical industrial equipment. Consistent magnetism and mechanical reliability directly determine machine operation safety. Fullzen implements full-process quality control from raw rare earth materials to finished products.

Raw material control: High-purity rare earth raw materials with batch composition, oxygen content and impurity testing before production

In-process monitoring: Real-time sinter curve tracking, magnetic testing on furnace test pieces to guarantee batch consistency

Finished product inspection: 100% full inspection for dimensions, flux and appearance; all oversized rings pass non-destructive crack scanning

Global standard certifications: ISO9001:2015, IATF16949, RoHS, REACH compliant

Reliability aging tests: Temperature cycling, salt spray, vibration shock, magnetic demagnetization aging and tensile strength testing

Why Choose Fullzen as Your Large Magnet Supplier?

With 10 years focused experience in bonded magnet R&D and manufacturing, Fullzen has supplied stable magnet ring solutions to over 200 motor and sensor clients worldwide, delivering more than 300 million bonded magnets in total.

Full independent industrial chain: Self-developed powder formula, mold design, molding and testing systems

Professional engineering support: Free magnetic circuit simulation and pole optimization for motor performance upgrading

Fast mold development: 7-day shortest sample lead time, 30% faster than average industry cycle

Strict quality standard: CPK ≥1.33, inter-batch flux deviation controlled within ±3% for automotive-grade products

Flexible production capacity: Smooth transition from small trial batches to mass volume production

Magnetic shielding safe packaging: Custom anti-magnetic cartons and wooden crates to meet air & sea freight transport standards

Dedicated after-sales technical team: 24-hour email & message response, on-site support available for major projects

FAQ

What is the maximum size of monolithic neodymium ring magnets you can produce? How to handle extra-large sizes?

Our solid sintered neodymium rings reach up to 500mm OD and 300mm height. For applications requiring diameters over 500mm, we supply segmented tile splicing solutions with unlimited theoretical size. Our largest finished spliced ring delivered so far hits 2.2 meters OD, with magnetic performance retaining over 95% of monolithic rings while cutting total cost to 50%–70%.

What magnetic uniformity tolerance can you guarantee for large ring magnets? How do you test it?

Fullzen controls flux deviation within ±3% for a single large ring magnet, far better than the industry average ±5%. Every finished ring undergoes multi-point gauss testing and full flux inspection. For ultra-high precision demands, we can provide full 3D magnetic field distribution diagrams for intuitive field analysis.

Why do large neodymium rings crack easily? How do you prevent hidden cracks?

Cracking roots from accumulated internal stress during sintering and mechanical stress during CNC machining. Larger sizes create higher stress risks. Fullzen solves this via four measures: uniform density isostatic pressing, slow staged sinter heating & cooling curves to reduce stress, limited 0.1mm single grinding depth, and 100% non-destructive crack scanning for all oversized finished magnets.

What magnetization modes do you support for large ring magnets? How many poles can you produce?

We offer axial magnetization, radially magnetized ring magnets, multi-pole circumferential magnetization (8/12/24/48 poles common) and Halbach array special layouts. Pole quantity has no rigid upper limit, restricted only by magnetizer coil size and ring dimension. Our equipment supports up to 120 poles for 500mm OD rings with pole arc accuracy ±0.5°.

How do you ship large strong ring magnets? Will transport reduce magnetic strength? Are shipping fees expensive?

Powerful neodymium rings require magnetic shielding packaging to meet international transport safety standards (outer surface magnetic field below 200Gs). Fullzen’s packaging solution uses foam buffer inner layer, iron sheet magnetic shielding middle layer and solid wooden crate outer reinforcement, compliant with air and sea shipping rules. Standard shipping does not demagnetize magnets; demagnetization only occurs above rated working temperature or strong reverse external magnetic fields. We will offer the most cost-effective logistics plan based on weight and your preferred delivery method.

Can you provide free magnetic circuit design support? What parameters do I need to offer?

Our professional magnetic engineers provide free sizing and FEA simulation support. Please share basic details including ring OD/ID/height, working ambient temperature, required magnetic flux or surface gauss, magnetization type, installation method and target application. We will recommend matching magnet grades, structure schemes and provide cost estimation within 24 hours.

What is your minimum order quantity for large ring magnets? Can I place small trial orders?

MOQ for standard large ring sizes is 1 unit for sample testing; mass production MOQ ranges 10–50 pieces based on dimension. Custom non-standard rings need new molds so trial order quantity will be adjusted accordingly. We welcome small batch prototype orders for product iteration and offer stocking inventory service for long-term strategic clients.

Is spliced ring magnet mechanical strength reliable? Will tiles fly apart under high-speed rotation?

Mechanical safety is the core priority for spliced ring design. Fullzen adopts multi-layer protection: ultra-precise tile machining with splicing gap ≤0.1mm paired with high-strength structural adhesive, optional outer stainless steel sleeves or carbon fiber winding for radial binding, inner iron liners for structural reinforcement, plus bolt or interference fit mechanical fixing as secondary security. Our spliced rings have passed overspeed and dynamic balance tests under 15,000 RPM and operate stably in commercial high-speed motors.

Related Ring Magnet Products

Explore our full range of neodymium ring magnets to find matching magnetic solutions for your equipment.

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Request Your Free Quote Toda

Share your target large ring magnet dimensions, magnetization requirements and equipment application details. Our Fullzen technical team will send you a customized large neodymium ring magnet solution and formal quotation within 24 hours.