Resources / sourcing
N42 vs N42SH: Grade, Temperature and Export Timing
A direct comparison of two grades that share an energy-product number but create different technical and sourcing decisions.
Reference note: Market prices and capacity figures are volatile reference points, not quotations or guarantees of current availability.
| Question | N42 | N42SH |
|---|---|---|
| Grade family | Nominal N42 energy-product family | Nominal N42 energy-product family with SH coercivity suffix |
| Indicative maximum use temperature | 80°C in the cited Arnold grade table | 150°C in the cited Arnold grade table |
| Composition case used here | Typically light rare earths only | Contains dysprosium in the verified August 2026 case |
| China export path | Typically outside the Dy/Tb-specific rule | Non-automatic export licence required |
| Schedule question | Confirm production and freight | Separate production, licence, export and freight |
These are manufacturer-specific reference values, not universal design limits. Geometry, magnetic circuit and the supplier’s grade data remain decisive.
The short comparison
N42 and N42SH share the number 42, but that does not make them interchangeable. The number identifies a maximum-energy-product family. The SH suffix indicates a higher intrinsic-coercivity category intended for more demanding temperature or demagnetizing conditions. Procurement should therefore read the complete designation, not compare the two offers as equivalent “N42 magnets.”
The technical distinction also changes the sourcing case. In the August 2026 case used throughout this site, N42SH contains dysprosium. A China-produced NdFeB magnet containing dysprosium or terbium requires a non-automatic export licence. A standard N42 typically uses only light rare earths and follows a different export path under that specific rule.
What the number 42 communicates
The number in an NdFeB designation relates to the maximum-energy-product family measured under defined conditions. It helps describe how much magnetic energy a material can provide, but it does not specify every property required by the application. Coercivity, temperature behavior, geometry and the magnetic circuit remain separate parts of the design decision.
Selecting a higher number is not automatically an improvement. A compact assembly may benefit from higher energy density, while another design may place greater value on demagnetization resistance at temperature. The controlled drawing and approved material specification must capture the actual requirement. A sourcing comparison should preserve that decision rather than silently optimize for catalogue availability.
What SH changes
SH is a coercivity and temperature-category suffix. In Arnold Magnetic Technologies’ published grade table, N42 appears with an indicative maximum use temperature of 80°C, while N42SH appears at 150°C. Those values demonstrate the category difference, but they are not universal application limits and should not be copied into a drawing without supplier and engineering review.
Maximum use temperature depends on more than the printed grade. The magnet’s geometry, operating point, air gap, opposing fields, duty cycle and thermal environment influence irreversible demagnetization risk. The supplier’s demagnetization curves and the buyer’s magnetic-circuit analysis are therefore more useful than treating one catalogue temperature as a guarantee for every part shape.
Why composition enters the RFQ
Higher-coercivity NdFeB grades may use heavy rare earths to improve resistance to demagnetization at elevated temperature. Arnold’s technical material describes dysprosium and terbium grain-boundary diffusion as methods for increasing coercivity while limiting the reduction in remanence. The exact composition remains a supplier-specific fact that should be requested in writing.
For the N42SH sourcing case verified here, dysprosium is present. That fact matters commercially because China’s April 2025 controls cover NdFeB magnets containing dysprosium or terbium. A grade label should prompt the composition question; it should not be treated as a chemical certificate. Record both the designation and the supplier’s composition statement.
The two lead times in an N42SH quote
A factory may be able to state when material, machining, coating and inspection will be complete. That is production lead time. It does not determine when a controlled magnet can leave China. Licence applications frequently remain unresolved for 60–120 days or longer, and there is no statutory review period that provides a dependable approval date.
The quotation should therefore show production, licence status, export release and freight as separate lines or assumptions. If a delivery promise combines them without explanation, procurement cannot compare it with an N42 offer or with a source outside China. “Ready to ship” and “authorized to export” are different milestones for a controlled composition.
When a grade change is a sourcing option
A sourcing review can identify that N42 typically avoids the Dy/Tb-specific licence exposure while N42SH does not. It can also ask whether a potential manufacturer offers a different composition or origin. That information creates an option, not an approved substitution. Temperature and demagnetization performance belong to the responsible engineering decision.
If a supplier proposes N42, N42H or another grade against an N42SH drawing, require the deviation in writing. Ask for the offered magnetic properties, temperature data and composition statement. Keep the proposed grade, commercial benefit and export implication together so the buyer can review the complete tradeoff instead of approving a material code in isolation.
When the grade stays N42SH
If engineering confirms that N42SH is required, sourcing can still change the exposure by examining manufacturing origin. The non-China supply map records named capacity in Estonia, the United States, Japan and planned capacity in Vietnam. Identification is only the first step; the manufacturer must still quote the exact geometry, grade, coating, tolerance and volume.
For each option, ask where alloy preparation, sintering, machining, coating, magnetization and inspection occur. A distributor address or final assembly location does not establish magnet origin. Compare current availability and documentation rather than assuming that publicly announced capacity is accessible to the program. Keep operating and planned capacity clearly separated.
A comparison-ready RFQ
State the drawing revision, N42 or N42SH designation, operating-temperature context, dimensions, tolerances, coating, magnetization direction, prototype quantity, annual volume, destination and required origin. Ask every potential source to repeat the offered grade and list deviations. When licensing may apply, request a separate statement of composition and export assumptions.
The delivered-date comparison should show the same milestones for every source: material availability, tooling, sample production, inspection, licence if applicable, export, freight and customs. This prevents a shorter factory estimate from winning against a more complete quote. A comparable schedule is built from explicit stages, not from the smallest number printed beside “lead time.”
The decision record
Record which grade was approved, the application temperature used in that decision, the supplier’s composition statement, manufacturing origin and whether an export licence is required. Attach the quotation revision and keep later changes as new dated records. This preserves why N42 or N42SH was selected when schedules or sources change.
The practical difference is concise: N42 and N42SH can share an energy-product number while requiring different coercivity, composition evidence and export planning. Treat the suffix as a technical and supply-chain input. Once those facts are explicit, engineering can own the material decision and procurement can compare delivery paths on the same basis.
Questions buyers ask
Is N42SH simply a stronger N42?+
No. The shared number identifies an energy-product family; SH indicates higher intrinsic coercivity and a different temperature category.
Can N42 replace N42SH?+
Only after the responsible engineering process confirms that the application and demagnetization conditions allow the change.
Why does N42SH affect export timing?+
In the verified case N42SH contains dysprosium, which places a China-produced magnet under the non-automatic export-licence regime.
Technical references
Continue the decision
NdFeB Grade Chart: N35–N52 and Temperature Suffixes
A procurement reference for reading the number, coercivity suffix and indicative temperature category before preparing an RFQ.
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