Custom sintered neodymium (NdFeB) magnets in blocks, arcs, rings, discs, and precision machined geometries for production programs.
Motors, actuators, sensors, high-force devices
Neodymium magnets are permanent rare earth magnets made from neodymium, iron, and boron (NdFeB). Sintered NdFeB combines high magnetic output with compact size, making it useful in motors, sensors, actuators, holding devices, and magnetic assemblies. The material, shape, coating, and magnetization must work together in the final design.
Choose the grade around required output and demagnetization margin, including the magnet's actual operating temperature and reverse field exposure.
Define the finished geometry, coating, magnetization direction, and measurable acceptance method together.
Axis Magnetics supports custom industrial sourcing, sample review, and production qualification for application-specific neodymium magnet programs.
Material selection
The number in an N grade describes an approximate maximum energy product class. It does not specify a magnet's pull force, dimensions, coating, or usable temperature.
Scroll the table horizontally to compare columns.
| Example grade | Remanence, Br (T) | Energy product, (BH)max (MGOe) |
|---|---|---|
| N35 | 1.17–1.21 | 33–35 |
| N42 | 1.30–1.32 | 40–42 |
| N52 | 1.45–1.48 | 49.5–52 |
N52 has a higher energy product than N42. For the same geometry and circuit, it can provide higher output. Actual holding force also depends on the air gap, steel target, orientation, and test method. Br is a material property, not the surface gauss reading of a finished part.
Suffixes such as H, SH, and UH distinguish higher coercivity classes used for elevated-temperature applications. They do not establish a universal safe operating temperature. Confirm the grade-specific demagnetization curve, magnet geometry, reverse field, and duty cycle.
These examples explain grade terminology; they are not Axis Magnetics acceptance limits or a guarantee of availability. A higher N number alone does not mean better thermal performance or a better fit for the application.
Shape and magnetization
Specify dimensions and magnetization separately. Two magnets with the same outside shape can produce different fields when the magnetization direction or pole pattern changes.
Length × width × thickness
Define the magnetization axis, edge breaks, datum surfaces, and dimensional limits after coating.
Diameter × thickness or length
Confirm axial or diametric magnetization. A round shape alone does not define the pole locations.
Outside diameter × inside diameter × thickness
Confirm the bore, wall thickness, and required axial, diametric, radial, or multipole pattern. Feasibility needs a separate review.
For arc and rotor magnets, also define the inner and outer radii, included angle, axial length, polarity, and assembly reference. These diagrams show dimension names only; they do not define tolerances or a production drawing.
Review custom neodymium magnet drawing requirementsSintered NdFeB needs corrosion protection matched to the environment. A coating name alone does not establish waterproof performance, salt-spray life, or suitability for immersion.
Scroll the table horizontally to compare columns.
| Protection option | Where it may fit | What to validate |
|---|---|---|
| Nickel-copper-nickel (NiCuNi) | A hard metallic finish commonly used for protected indoor applications. | Check scratches, exposed edges, humidity, adhesive compatibility, and electrical conductivity. |
| Epoxy | A polymer barrier considered where moisture exposure or electrical isolation matters. | Validate coating coverage, damage resistance, bonding, and the actual corrosion test. |
| Zinc | A metallic protection option that may suit some industrial environments. | Specify the finish and corrosion requirement; appearance and protection depend on the process. |
| Encapsulation or overmolding | A surrounding barrier or carrier that can combine protection with mechanical retention. | Review sealing, molding temperature, fit, and the added distance to the mating surface. |
Coating thickness affects finished size and assembly clearance. Agree on the coating system, measurement stage, handling, and acceptance test before approving samples.
Read the NdFeB coating selection guideA grade number alone cannot predict holding force or sensor output. Magnet thickness, pole area, magnetization direction, air gap, surrounding steel, and target geometry all affect performance. Compare samples with the same fixture and test conditions; distinguish direct pull from shear loading and define the measurement location for field readings.
Neodymium magnets lose some output as temperature rises. Some change can recover after cooling, while an operating point beyond the demagnetization knee can cause permanent loss. Review hot and cold conditions, magnet geometry, reverse fields, and end-of-life margin rather than treating a catalog temperature as a design guarantee.
HRE-Free NdFeB remains a rare earth magnet because it contains light rare earth material such as neodymium. An HRE-Free specification excludes heavy rare earth elements; dysprosium-free alone does not establish terbium-free or HRE-Free composition. Confirm composition documentation and compare output, coercivity, and thermal margin against the current requirement.
Agree on the drawing revision, material specification, finished dimensions, coating requirements, polarity marking, packaging, and test method before sampling. Compare dimensional and magnetic results with defined acceptance limits, then identify which checks apply to production lots. This makes an alternate-source comparison more useful than comparing grade labels alone.
Review material options, custom specifications, and qualification guidance for the next step in your sourcing program.
Neodymium magnets are one family of rare earth magnets. Samarium cobalt (SmCo) is another. NdFeB describes neodymium iron boron; rare earth does not mean every rare earth magnet has the same composition or temperature behavior.
Common uses include compact electric motors, sensors, actuators, latches, holding devices, and magnetic assemblies where high output is needed in limited space. Selection depends on the complete magnetic circuit and operating environment.
N52 has a higher maximum energy product, but the best choice also depends on temperature, reverse field, geometry, coating, and required margin. A higher N number does not automatically give better resistance to demagnetization at operating temperature.
Sintered NdFeB is corrosion-sensitive and normally needs a protective finish or surrounding barrier. Choose the coating around moisture, handling, adhesive bonding, temperature, and the specified validation test. A plated finish alone does not establish waterproof performance.
Axis Magnetics can review blocks, discs, rings, arcs, rotor segments, and other custom sintered NdFeB geometries. The review includes finished dimensions, magnetization, edge condition, coating, inspection, and the intended production program.
Do not treat finished neodymium magnets like ordinary metal parts. The material is brittle, machining can damage protective coatings, and grinding dust can ignite. Plan holes and finishing into the controlled production process instead.
Useful inputs include a drawing, application target, magnet temperature, grade direction, coating, magnetization, test method, volume, and qualification requirements. Start with basic contact details; Axis can discuss the technical inputs in follow-up.