Alias size
0.315 in x 0.118 in
Equivalent to about 8.00 mm diameter x 3.00 mm thickness, a small N52 disc format.
Check whether an N52 disc magnet size is plausible, estimate weight and axial pull, then use the report layer to decide grade, coating, risk controls, and next RFQ inputs.
For the searched phrase 0.315in dia.x 118 in thk neodymium disk magnets N52, this page normalizes the buyer intent to the practical 0.315 in diameter x 0.118 in thickness disc before any quote or sample decision.
Default alias size
8 x 3 mm
N52 grade marker
49-53 MGOe
Best next step
Sample test
N52 Disc Magnet Quick Check
Defaults are set to 0.315in dia.x 0.118 in thk neodymium disk magnets N52, the alias size merged into this canonical N52 disc magnet page.
This matches the alias size 0.315in dia.x 0.118 in thk neodymium disk magnets N52.
Estimated pull
10.49 lbf
46.7 N, axial pull on clean thick steel
Single magnet weight
1.145 g
Batch weight
1.15 kg
Volume
0.1507 cm3
Conservative shear hold
1.89 lbf
Alias size
0.315 in x 0.118 in
Equivalent to about 8.00 mm diameter x 3.00 mm thickness, a small N52 disc format.
Material class
49-53 MGOe
Arnold Magnetic Technologies lists N52 BHmax at 49-53 MGOe with typical Br around 14.2-14.8 kG.
Weight estimate
about 1.15 g
Using 7.6 g/cm3 density for an 8 mm x 3 mm sintered NdFeB disc.
Use boundary
Validate by fixture
Pull force is an assembly-level result; target steel, air gap, shear load, coating, and temperature can change the outcome.
Use N52 disc magnets when the assembly has a fixed small envelope and the required force cannot be reached with a lower grade. The 0.315in dia.x 0.118 in thk neodymium disk magnets N52 phrasing is answered here as the same intent cluster, not as a separate URL.
The important boundary is that N52 is a material grade signal, not a finished assembly guarantee. It helps screen magnetic energy density, but the RFQ still needs test geometry, coating, temperature, magnetization direction, and safety constraints.
If the searched requirement is a broader 0.5 inch magnet N50 rather than this N52 disc alias, use the canonical N50 magnet quick check before comparing grades.
This page uses public supplier technical data and exact unit conversion for screening. It does not claim a certified pull force because pull force is an assembly-level test result, not a grade name alone.
| Evidence point | Value used | Source / boundary |
|---|---|---|
| N52 grade strength | BHmax 49-53 MGOe; nominal Br 14.5 kG | Arnold Magnetic Technologies N52 data sheet, Rev. 210802, accessed June 6, 2026. |
| Selection limits | Temperature, geometry, application requirement, and cost must be checked | Dura Magnetics N52 technical note, accessed June 6, 2026. |
| Grade naming boundary | N52 describes magnetic material properties, not a guaranteed pull force for every disc assembly | MMPA Permanent Magnet Guidelines and public supplier data sheets, accessed June 6, 2026. |
| Consumer safety boundary | High-powered small magnets are treated as a regulated ingestion hazard in consumer products | U.S. Consumer Product Safety Commission magnet safety rule and magnet information center, updated 2022 and accessed June 6, 2026. |
| Alias dimension conversion | 0.315 in = 8.001 mm; 0.118 in = 2.997 mm | Exact inch-to-mm conversion using 25.4 mm per inch. |
| Mass estimate | Disc volume x 7.6 g/cm3 density | Density value from Arnold N52 data sheet; final lot weight should use supplier inspection data. |
These fields are the difference between a searchable part phrase and a buildable procurement specification. They should be frozen before pilot or production release.
| Field | Recommended RFQ wording | Why it matters |
|---|---|---|
| Grade | N52, with supplier data sheet and lot traceability | The grade name should map to Br, Hcb, Hcj, and BHmax ranges. It should not be used as a substitute for a finished-part pull requirement. |
| Magnetization | Axial through 0.118 in / 3 mm thickness unless stated otherwise | Most disc magnets are axial, but diametric magnetization changes the usable field direction, fixture, inspection method, and lead time. |
| Operating temperature | State continuous and peak temperature; review H/SH/UH/EH variants for sustained heat | N52 maximizes room-temperature energy product. Thermal margin can dominate grade choice in motors, sensors, and enclosed assemblies. |
| Coating | Ni-Cu-Ni for indoor use; epoxy or zinc only after exposure review | Sintered NdFeB is corrosion-sensitive. Coating choice affects corrosion resistance, adhesive bonding, thickness stack-up, and edge-chip acceptance. |
| Pull validation | Define target steel grade/thickness, gap, pull direction, fixture, speed, and pass value | A catalog pull number cannot be compared unless the test condition is known. Air gaps, paint, thin sheet, and shear loading change the result. |
Scenario 1
Use the calculator to screen size and mass, then validate axial pull with the real bracket coating.
Scenario 2
Check shear load separately; a cup assembly or steel return path may outperform a loose disc.
Scenario 3
Use 8 mm x 3 mm N52 discs for trials, but freeze coating and tolerance before production RFQ.
N52 is often the right answer only when geometry is fixed and the assembly is room-temperature. The table below shows when a different design move can beat a higher grade.
If yes: Compare N42/N45/N52 because geometry gain may be cheaper than jumping to the highest room-temperature grade.
If no: N52 becomes more relevant, but pull and thermal validation still decide whether it works.
If yes: Ask for high-temperature grade review instead of assuming standard N52 has enough irreversible-loss margin.
If no: Standard N52 can be screened for compact room-temperature assemblies.
If yes: Add a mechanical stop, pocket, cup, adhesive validation, or retaining feature. Axial pull estimates do not prove shear holding.
If no: Use axial pull screening, then validate on the real mating surface.
If yes: Treat ingestion, pinch, labeling, and regulatory review as design inputs before procurement.
If no: Industrial RFQs still need handling instructions, separation packaging, and incoming inspection criteria.
| Option | Best for | Tradeoff |
|---|---|---|
| N52 disc magnet | Small envelope with maximum room-temperature strength | Higher cost, lower thermal headroom than H/SH high-temp grades |
| N42/N45 disc magnet | Cost-sensitive fixtures where size can increase slightly | Lower energy product; may require larger diameter or thickness |
| N52 block or ring | Directional assembly constraints or mechanical locating features | Different tooling, tolerances, and magnetization checks |
| Assembly with steel cup | Holding applications that need more usable surface pull | Changes flux path, part envelope, corrosion design, and cost |
Impact: Some searches write 118 in thk when they mean 0.118 in or 1/8 in. Quoting 118 inches would be impossible for this intent.
Mitigation: Treat the alias as 0.315in dia.x 0.118 in thk neodymium disk magnets N52 and confirm drawing units before PO.
Impact: Air gap, paint, target steel, and shear loading can cut usable holding force sharply.
Mitigation: Use the quick check for RFQ screening, then request a sample pull test with the real mating surface.
Impact: N52 may add cost without improving the assembly if temperature, geometry, or steel saturation is the bottleneck.
Mitigation: Compare N42/N45/N52 against required safety factor, operating temperature, and available envelope.
Impact: Small discs are brittle and edge chips can start corrosion or reduce usable contact area.
Mitigation: Specify Ni-Cu-Ni, epoxy, zinc, or custom coating with salt-spray and handling acceptance criteria.
Impact: Small high-powered magnets can create ingestion and pinch hazards if they are accessible outside a controlled assembly.
Mitigation: For consumer-facing products, run product-safety and regulatory review before sourcing; for industrial assemblies, define retention, labeling, and packaging controls.
Updated June 6, 2026. The added conclusions above use public supplier data, standards pointers, and safety resources. Where the final value depends on a buyer-specific fixture, the page marks the result as screening guidance rather than certified data.
Used for N52 magnetic property range and density screening values. Accessed June 6, 2026.
Used for selection caveats around temperature, geometry, cost, and application constraints. Accessed June 6, 2026.
Used as a standards pointer for permanent magnet material guidelines and grade-property framing. Accessed June 6, 2026.
Used for the consumer-accessible small high-powered magnet safety boundary. Updated 2022; accessed June 6, 2026.
No. It is handled as an alias of the canonical N52 disc magnet intent. In normal buyer language, the likely size is 0.315 inch diameter x 0.118 inch thickness, about 8 mm x 3 mm.
N52 is a high-energy sintered NdFeB grade. Public supplier data commonly places N52 maximum energy product near 52 MGOe, but final performance depends on shape, temperature, coating, and magnetic circuit.
No. The calculator is an RFQ preparation tool. Guaranteed pull force requires test method, target steel, coating, temperature, magnetization direction, and tolerance agreement.
Not always. N52 is useful when the envelope is fixed and room-temperature strength is the limiting factor. If cost, heat, or target steel saturation dominates, a lower grade or assembly change can be better.
Send diameter, thickness, tolerance, grade, coating, magnetization direction, quantity, destination, operating temperature, mating surface, and required validation tests.
Ni-Cu-Ni is common for general indoor use. Epoxy or other coatings may be better when corrosion, salt spray, adhesive bonding, or handling damage is a concern.
Yes, but tooling, tolerance, coating thickness, and magnetization fixtures determine the practical minimum order and lead time. Prototype samples should validate both dimensions and pull force.
Different sellers use different steel plates, air gaps, coatings, test fixtures, and safety assumptions. Compare test conditions before comparing catalog numbers.
Standard N-grade NdFeB is usually treated as a room-temperature to moderate-temperature material. For sustained heat, ask for H, SH, UH, or EH grade review rather than assuming N52 will hold margin.
Yes. Most small disc magnets are axially magnetized through thickness, but diametric or multipole requirements must be stated explicitly because fixtures and inspection differ.
Use incoming inspection for dimensions, coating, visual defects, surface flux or moment, pull test on a controlled fixture, and traceability documents for material grade.
Avoid them when users can pinch fingers, swallow parts, expose them to heat, place them near electronics, or use them in uncontrolled impact conditions without a retaining design.
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