What is a 34 grade samarium cobalt magnet?

In public 34 grade references, it is typically a high-energy sintered Sm2Co17 magnet around 34 MGOe maximum energy product. Buyers should still confirm the supplier property table because grade naming is not perfectly portable.

Is 34 grade SmCo the same as SmCo5?

No. Public 34 grade data is associated with Sm2Co17, while SmCo5 is a 1:5 family with different energy-density and application trade-offs.

What applications best justify 34 grade SmCo?

The strongest fits are compact high-temperature motors, generators, actuators, RF magnetic circuits, aerospace assemblies, oil and gas tooling, and some medical equipment where space, heat, and reliability interact.

Can 34 grade SmCo run at 300 C?

EEC publishes 300 C as a typical maximum operating temperature for 2:17-34, but the same sheet notes operating temperature depends strongly on geometry and operating point. Treat 300 C as a screening value, not automatic approval.

Why does the tool estimate Br retention?

It applies the public reversible Br temperature coefficient as a first-pass estimate. The EEC 34 grade sheet says the Br coefficient is calculated between -50 C and 150 C for reference, so values outside that band should be treated as screening only. Final field output still needs supplier curves and application-level magnetic modeling.

What does 18 kOe intrinsic coercivity mean for selection?

It is a public minimum reference for iHc in the EEC sheet. Reverse-field exposure still needs load-line review because magnet shape and circuit conditions change the operating point.

Should I choose 34 grade whenever I need high temperature?

No. If the package envelope is loose or the application is cost-sensitive, a lower Sm2Co17 grade, SmCo5, or high-temperature NdFeB may be more practical.

Is 34 grade SmCo corrosion-proof?

No. SmCo is generally more corrosion-resistant than NdFeB, but water, cleaning chemistry, oilfield media, and galvanic contact can still require coating or sealing review.

Why do suppliers list nearby grades instead of exactly 34?

Grade systems differ by supplier. Arnold, for example, publishes nearby high-energy grades such as 33E and 35E, while other public tables may stop at S32 and require contact for custom grades.

What should an RFQ include for this grade?

Include target property window, dimensions, magnetization direction, continuous and peak temperatures, reverse-field exposure, coating/media requirements, inspection criteria, sample quantity, and documentation requirements.

Can the fit score replace supplier engineering review?

No. The score is a triage tool. It helps decide whether 34 grade deserves review, but production approval requires supplier curves, samples, and validation.

What is the biggest misuse risk for this page?

The biggest risk is treating 34 grade as a magic label instead of verifying properties, geometry, coating, and operating point.

When is 35E-class SmCo worth comparing?

Compare it when the design is package-density limited and a supplier offers a nearby high-energy grade with stronger documented fit for the application.

When is SmCo5 worth comparing?

Compare SmCo5 when corrosion resistance, simpler sourcing, or moderate high-temperature duty matters more than maximum energy product.

What validation is minimal before scaling production?

Run incoming magnetic property checks, geometry inspection, coating or sealing checks if used, thermal cycling, and application-level field verification.

Does 34 grade SmCo remove critical-material risk?

No. It may reduce exposure to Dy/Tb-heavy high-temperature NdFeB in some designs, but cobalt is on the 2023 DOE critical materials list and samarium is on the USGS critical minerals list. Treat this as a supply-chain trade-off, not a risk-free substitution.

When should DFARS 252.225-7052 matter?

It matters when the magnet or assembly may enter a covered U.S. defense acquisition. The clause covers samarium-cobalt magnets, and its January 1, 2027 language expands the restricted scope to the full supply chain from cobalt and samarium ore or feedstock through finished magnets.

Which standard should I reference for sintered SmCo?

ASTM A1102-19 is the public standard specification for sintered samarium cobalt permanent magnets. For magnetic curve measurement, its abstract references ASTM A977/A977M. Confirm the exact revision and acceptance criteria with your quality team.

Is RECOMA 35E the same as 34 grade?

No. Arnold publishes 35E as a high-energy SmCo grade with nearby performance, but it is not automatically equivalent to EEC 2:17-34. Compare BHmax, Br, Hcb, Hcj, temperature coefficient, maximum operating temperature, and demagnetization curves.

What public data is still unavailable?

A universal public derating table for every 34 grade shape, coating, operating point, and corrosion environment was not found. Treat shape-specific irreversible loss, coating survival, and chipping risk as pending until supplier sample data is reviewed.

Hybrid Tool + Technical Report

34 Grade Samarium Cobalt Magnet Applications

Run the application-fit tool first to decide whether 34 grade SmCo deserves an RFQ review. Then use the same page to check evidence, temperature limits, supplier naming differences, alternatives, and risk controls.

Run fit tool Start RFQ review

Published: 2026-06-07 · Last reviewed: 2026-06-07

34 Grade SmCo Application Fit Tool

Score whether 34 grade samarium cobalt is a defensible first-choice material for your application. The tool uses public 2:17-34 reference values, then flags where supplier-specific evidence is still required.

Executive Summary

34 grade usually means a high-energy sintered Sm2Co17 path

Public EEC 2:17-34 data lists typical BHmax 34 MGOe, minimum 32 MGOe, typical Br 11.9 kG, and minimum intrinsic coercivity 18 kOe.

[R1] Reviewed 2026-06-07

Use it when package density and heat matter together

The strongest application fit is not generic pull force. It is compact magnetic output under elevated temperature, reverse-field, or reliability constraints.

[R1][R2][R3] Reviewed 2026-06-07

300 C is a reference limit, not a universal approval

EEC lists 300 C maximum operating temperature but notes operating temperature depends strongly on geometry and operating point.

[R1] Reviewed 2026-06-07

Grade names are not perfectly portable across suppliers

Arnold publishes nearby high-energy grades such as 33E and 35E, while Goudsmit common-grade tables stop at S32 and ask buyers to contact them for other grades.

[R4][R5] Reviewed 2026-06-07

The right RFQ asks for curves, not only a grade label

Demagnetization curves by temperature, load-line assumptions, coating plan, and geometry-specific inspection limits are the evidence needed for production decisions.

[R1][R4][P1] Reviewed 2026-06-07

High-energy SmCo can reduce Dy/Tb exposure but not critical-material risk

DOE listed cobalt, dysprosium, neodymium, praseodymium, and terbium as 2023 critical materials for energy; samarium is also on the USGS critical minerals list. SmCo may reduce heavy-rare-earth NdFeB dependency, but it still needs supply-chain review.

[R7][R8] Reviewed 2026-06-07

Stage1b Gap	Research Added	Decision Impact	Source
Temperature limit looked too absolute	EEC 34 grade data gives a 300 C maximum operating temperature reference but explicitly ties actual maximum operating temperature to geometry and operating point. The EEC technical brief also frames 2:17-34 as a grade that can operate up to 300 C depending on magnetic-circuit design.	A buyer should treat 300 C as a screening ceiling and ask for geometry-specific curves before approving any peak or continuous duty near that value.	[R1][R6]
Grade portability needed stronger proof	Arnold lists RECOMA grades from 18 through 35E and publishes 33E/35E-class high-energy options, while Goudsmit common grades stop at S32 and state that other grades require supplier contact.	RFQs should compare BHmax, Br, Hcb, Hcj, temperature coefficient, maximum operating temperature, and curve evidence rather than asking every supplier for exactly "34 grade".	[R4][R5]
Standards and test method context was missing	ASTM A1102-19 covers sintered SmCo permanent magnets, identifies SmCo 1:5 and SmCo 2:17 families, and points demagnetization-curve characterization to ASTM A977/A977M.	For regulated or audited programs, include the standard/test-method expectation in the drawing or quality clause instead of accepting a catalog table alone.	[R9]
Supply-chain risk was described generically	The 2023 DOE critical materials notice lists cobalt, dysprosium, neodymium, praseodymium, and terbium as critical materials for energy, and the USGS critical-minerals list includes samarium.	SmCo can be a hedge against Dy/Tb-heavy high-temperature NdFeB in some motors, but cobalt and samarium sourcing still need program-level review.	[R7]
Defense procurement impact was under-specified	DFARS 252.225-7052 covers samarium-cobalt magnets and, effective January 1, 2027, expands the restriction to the entire supply chain from cobalt and samarium ore/feedstock through finished magnets for covered contracts.	Defense and aerospace RFQs should ask early for origin, melt/production route, and documentation capability; late discovery can invalidate a material choice.	[R8]

Fit Segment	Profile	Decision Signal
Strong fit	Continuous temperature above 150 C, package density is critical, reverse-field exposure is modeled, and sourcing documentation matters.	Start with 34 grade or supplier-equivalent high-energy Sm2Co17, then request curves for the exact geometry.
Conditional fit	Thermal load is real but package pressure is moderate, or geometry is thin/chip-sensitive.	Compare 32 MGOe Sm2Co17, 35E-equivalent high-energy SmCo, and a custom grade before committing.
Poor first choice	Application stays below 120-150 C, has low reverse-field exposure, and has no tight package-density or compliance pressure.	A lower grade, SmCo5, or high-temperature NdFeB may be more economical.

Public 34 Grade Data and Application Evidence

This section separates known public properties from assumptions that still require supplier-specific review. The values below should be used for screening, not final magnetic-circuit approval.

Property	Public Value	Decision Use	Source
Maximum energy product	Typical 34 MGOe; minimum 32 MGOe	Package-density signal for compact motors, actuators, and assemblies.	[R1]
Residual induction Br	Typical 11.9 kG / 1.19 T; minimum 11.7 kG / 1.17 T	Starting point for magnetic-circuit output modeling.	[R1]
Coercivity Hc	Typical 11.1 kOe; minimum 10.8 kOe	Useful screening value, but not enough for reverse-field approval.	[R1]
Intrinsic coercivity iHc	Minimum 18 kOe / 1433 kA/m	Primary public guardrail for demagnetization margin.	[R1]
Reversible temperature coefficient of Br	Typical -0.035%/C	Estimate reversible flux-density drift; EEC notes one public 34 grade source calculates this between -50 C and 150 C, so do not extrapolate blindly to 300 C.	[R1][R5]
Maximum operating temperature	Typical 300 C reference	Thermal screen only; final approval depends on geometry and operating point.	[R1]

Application	Why 34 Fits	Must Check	Evidence
High-speed motors and generators	High energy density can reduce rotor package size while SmCo keeps better hot-zone stability than many NdFeB paths.	Rotor retention, thermal soak, reverse-field margin, and balance after coating or sleeve decisions.	[R1][R4]
Aerospace actuators and aircraft assemblies	Compact magnetic output, elevated-temperature stability, and compliance-sensitive sourcing can matter more than lowest room-temperature cost.	Traceability, DFARS clauses where applicable, thermal cycling, vibration, country-of-origin evidence, and lot documentation.	[R1][R4][R8]
Microwave signal amplification and RF circuits	Stable field behavior and controlled demagnetization curves support magnetic-circuit consistency.	Field map, temperature coefficient, geometry tolerance, and assembly retention method.	[R1]
Oil and gas exploration tooling	Temperature exposure and media risk can justify SmCo when lower-cost magnets lose margin.	Coating/sealing, pressure environment, shock, corrosion media, and peak temperature duration.	[R1][R3]
Biomedical and surgical equipment	Small, stable assemblies may benefit when cleaning exposure and repeatability requirements are defined.	Biocompatibility of surrounding assembly, cleaning chemistry, coating integrity, and documentation.	[R1]

Operating Condition	Implication	Caveat	Source
High package density + >150 C continuous operation	High-energy Sm2Co17 deserves first-pass review because the extra BHmax can reduce magnet volume while retaining hot-zone margin.	Still requires operating-point curves; do not use room-temperature BHmax as the only justification.	[R1][R4][R6]
Very high peak temperature near 300 C	Public data supports screening up to the 300 C class for specific 34/35E-type materials.	Peak dwell time, load line, geometry, and irreversible loss must be tested. Mark as pending until supplier curves are available.	[R1][R4][R6]
Harsh media, cleaning chemistry, or galvanic contact	SmCo has better corrosion positioning than many NdFeB choices, but it is not a no-review material.	Coating/sealing remains application-specific; public data is insufficient for universal corrosion approval.	[R2][R3][P1]
Loose package envelope or moderate temperature	34 grade is usually an expensive first choice when lower Sm2Co17, SmCo5, or high-temperature NdFeB can pass.	Use the tool score to trigger a fallback comparison, then validate with total cost and qualification time.	[R3][R5]
Thin rings, small arcs, sharp corners, or press-fit assembly	Material selection cannot be separated from geometry and handling risk.	No reliable public universal derating table was found; require supplier review and sample inspection data.	[P1]

Methodology

The tool and report follow a conservative screening method: first establish what is publicly known, then force every decision-critical unknown into the RFQ evidence list.

Step	Output	Evidence
1. Confirm grade meaning	Treat "34 grade" as a high-energy Sm2Co17 request unless supplier documentation says otherwise.	[R1][R4][R5]
2. Map thermal profile	Separate continuous temperature, peak temperature, dwell time, and thermal-cycle count.	[R1][R3]
3. Check magnetic load line	Request demagnetization curves at operating temperature and compare against reverse-field exposure.	[R1][R4]
4. Review geometry manufacturability	Thin walls, sharp corners, and small rings need edge protection and inspection planning because sintered SmCo is brittle.	[R3][P1]
5. Lock sourcing evidence	RFQ should ask for grade, curve set, coating plan, lot traceability, and sample validation scope.	[R1][R4][P2]

Standard / Compliance Item	Known Boundary	Buyer Action	Source
Material family	Public 34 grade evidence points to sintered Sm2Co17, not SmCo5.	Ask the supplier to state alloy family and grade table values in the quote.	[R1][R9]
Magnetic test evidence	A property table does not replace a demagnetization curve at operating temperature.	Specify demagnetization curves, test temperature, and whether ASTM A977/A977M or an equivalent method is required.	[R1][R9]
Critical-material exposure	SmCo avoids NdFeB reliance in some designs but still uses cobalt and samarium.	Document why SmCo is selected and whether a lower-grade SmCo or NdFeB alternative was rejected for technical reasons.	[R7]
Defense supply chain	Covered U.S. defense contracts can trigger magnet-origin and production restrictions.	Add DFARS review to the RFQ if the assembly may enter a covered defense program.	[R8]
Supplier equivalence	Nearby labels such as 33E, 35E, S32, or 32 MGOe-class Sm2Co17 are not automatically equivalent.	Use a side-by-side property and curve comparison before accepting substitution.	[R4][R5][P2]

Use / Do Not Use Boundaries

34 grade SmCo can be the right material only when its extra energy density and validation overhead solve a real constraint. If the constraint is weak, the grade can add cost without reducing risk.

Use 34 grade when

Package density is a hard design constraint.
Continuous hot-zone exposure is above typical NdFeB comfort.
Reverse-field exposure is modeled and still has margin.
Supplier curves and lot documentation can be reviewed.

Do not default to 34 grade when

Temperature is moderate and package volume is available.
The only requirement is generic holding force.
Geometry is very thin and no handling plan exists.
The supplier cannot provide property values and curves.

Public evidence is not enough to publish a universal 34 grade derating factor for every shape, coating, and magnetic circuit. Where this page says pending or supplier-specific, treat that as a required RFQ input rather than a missing catalog detail.

Scenario Examples

Compact high-speed rotor

Assumptions: 180 C continuous, high package-density priority, modeled reverse field below 8 kOe, sleeve retention planned.

Path: Tool should return strong or conditional fit; request 34 grade curves and rotor-specific thermal validation.

Result: 34 grade is defensible if supplier confirms geometry-specific loss and mechanical retention limits.

Aerospace actuator replacement

Assumptions: Thermal cycling to 230 C peak, traceability requirement, tight envelope, vibration exposure.

Path: Use 34 grade as a candidate, but require lot traceability, demag curves, vibration plan, and fallback grade comparison.

Result: Decision depends on evidence package, not the grade name alone.

Moderate-temperature sensor bracket

Assumptions: 90 C continuous, low reverse-field exposure, loose package envelope, cost-sensitive sourcing.

Path: Tool should push away from 34 grade first-choice status.

Result: Lower-cost SmCo or high-temperature NdFeB should be checked before high-energy SmCo.

Oilfield magnetic assembly

Assumptions: 250 C peak, cleaning fluids or downhole media, shock exposure, corrosion concern.

Path: 34 grade may fit only after coating/sealing and peak-duration assumptions are reviewed.

Result: Supplier engineering review is mandatory before production quote.

Alternatives and Trade-offs

Option	Strengths	Constraints	Best Use Case
34 grade Sm2Co17	High energy density with elevated-temperature SmCo behavior and compact assembly potential.	Requires tighter supplier evidence; may not be listed under the same naming system by every vendor.	High-speed motors, actuators, RF assemblies, and compact harsh-duty magnetic circuits.
32 MGOe-class Sm2Co17	More common public grade band; often easier to quote across suppliers.	Slightly lower package-density signal may require larger magnet volume.	Programs that need Sm2Co17 stability but can accept modestly larger geometry.
SmCo5	Good corrosion resistance and simpler lower-energy grade positioning.	Lower maximum energy product than high-energy Sm2Co17 options.	Compact parts where thermal needs are high but energy-density pressure is not extreme.
High-temperature NdFeB	Strong room-temperature output and often lower initial material cost.	Hot-zone performance, corrosion protection, and heavy rare-earth dependency can become limiting.	Moderate-temperature programs where cost and room-temperature field dominate.
Custom high-energy SmCo	Can tune performance and compliance path around a demanding application.	Longer development loop, higher validation cost, and stronger MOQ pressure.	Aerospace, defense, motorsport, or oilfield programs where the public grade table is not enough.

Risk Controls

Validation Gate	Pass Signal	Fail Signal
Gate 1: public-data screen	Application needs compact output, high temperature, and documented reverse-field margin.	Only generic holding force, moderate temperature, or low documentation demand.
Gate 2: supplier-equivalence screen	Supplier provides grade family, BHmax, Br, Hcb, Hcj, temperature coefficient, and matching curves.	Quote only says "34 grade" or substitutes a nearby grade without property comparison.
Gate 3: geometry and environment screen	Drawing, magnetization direction, thinnest section, coating/media exposure, and operating temperature profile are reviewed together.	Geometry or coating is left for later even though qualification depends on it.
Gate 4: program-risk screen	Critical-material, DFARS, traceability, and lot documentation needs are clear before sample order.	Compliance review starts after magnetic samples pass.

Risk	Trigger	Impact	Mitigation
Grade-label mismatch	Buyer asks for "34 grade" but supplier uses a different grade system or only publishes nearby grades.	Quotes become non-comparable and validation evidence is incomplete.	Request BHmax, Br, Hc, Hcj, temperature coefficient, and curve set rather than relying on label alone.
Thermal overclaim	Using the 300 C reference as a blanket approval for all shapes and operating points.	Irreversible loss or field drift can appear during qualification.	Validate continuous and peak conditions with supplier curves and sample thermal cycling.
Geometry damage	Thin sections, sharp edges, press-fit retention, or uncontrolled handling.	Chipping, cracks, failed inspection, and inconsistent field output.	Add chamfers, handling fixtures, edge inspection, and retention method review before sampling.
Corrosion or coating assumption	Assuming SmCo never needs coating in water, cleaning chemistry, oilfield media, or galvanic contact.	Surface degradation or assembly contamination risk remains hidden.	Specify media exposure and request coating/sealing recommendation with adhesion and inspection criteria.
Cost escalation	Selecting 34 grade for a moderate-duty application where lower grades would pass.	Unnecessary material, machining, and qualification cost.	Compare 32 MGOe-class Sm2Co17 and SmCo5 before final RFQ unless package density forces 34 grade.

RFQ Evidence Checklist

Send the fit-tool output with these fields so suppliers can quote comparable material, geometry, and validation scope.

Target grade or equivalent property window: BHmax, Br, Hc, Hcj, and temperature coefficient.

Drawing with dimensions, tolerances, magnetization direction, thinnest section, and edge requirements.

Continuous temperature, peak temperature, dwell time, thermal cycles, and reverse-field exposure.

Media exposure, coating or sealing requirement, cleaning chemistry, and corrosion acceptance criteria.

Sample quantity, forecast volume, inspection method, and magnetic test requirement.

Traceability, compliance, country-of-origin, or documentation clauses needed by the program.

For covered defense work, state whether DFARS 252.225-7052 review is required before sampling.

For audited qualification, state whether ASTM A1102 and ASTM A977/A977M or equivalent magnetic test methods apply.

If accepting a supplier-equivalent grade, attach the property-by-property comparison instead of relying on a grade label.

Related Decision Paths

34 grade characteristics interpreterUse this companion page when the question is what the 34 grade values mean before choosing an application path.Sm2Co17 magnet capability pageUse this to compare 34 grade assumptions against standard high-temperature Sm2Co17 sourcing paths.SmCo5 magnet alternativeCheck whether a lower-energy 1:5 option can meet your geometry and corrosion requirements.Aerospace application contextReview qualification and high-reliability requirements for elevated-temperature assemblies.High-temperature sensor use casesCompare grade choice against drift, repeatability, and thermal exposure requirements.Qualification and reliability workflowTranslate tool output into sampling, validation, and production acceptance gates.Engineering RFQ reviewSend the fit-tool output and ask for a supplier-side grade and geometry review.

FAQ

Sources, Dates, and Known Unknowns

ID	Source	Date	Coverage	Certainty
R1	Electron Energy Corporation 34 Grade SmCo Sell Sheet	PDF accessed 2026-06-07	EEC 2:17-34 properties: BHmax, Br, Hc, iHc, Br temperature coefficient, 300 C maximum operating temperature note, and listed applications.	Known public source
R2	Eclipse Magnetics SmCo technical data sheet	PDF accessed 2026-06-07	General SmCo application categories, temperature behavior, and Sm2Co17 corrosion context.	Known public source
R3	Bunting/e-Magnets Samarium Cobalt Magnets data sheet	PDF accessed 2026-06-07	Typical SmCo grade bands, maximum recommended temperatures, and Sm2Co17 temperature coefficient context.	Known public source
R4	Arnold Magnetic Technologies RECOMA SmCo grades page	Web page accessed 2026-06-07	Comparable high-energy SmCo grade table, applications for 33E/35E-class materials, and sourcing/compliance context.	Known public source
R5	Goudsmit Samarium Cobalt grade system	Issue date 2025-08-22; accessed 2026-06-07	Public common-grade table through S32 and note that other grades require supplier contact.	Known public source
P1	Universal 34 grade geometry derating table	As of 2026-06-07	No single public table was found that safely maps every 34 grade shape to loss, chipping, and coating outcomes.	Pending confirmation / supplier-specific review required
P2	Cross-supplier equivalent-grade guarantee	As of 2026-06-07	Public grade systems differ; equivalent-grade claims require property-by-property comparison.	Pending confirmation / do not assume equivalence
R6	Electron Energy Corporation technical brief: Advancements in Samarium Cobalt Magnetic Properties	PDF accessed 2026-06-07	2:17-34 development context, comparison against 2:17-33 and 2:17-31, and note that 300 C operation depends on magnetic-circuit design.	Known public source
R7	U.S. Department of Energy 2023 Critical Materials List / Federal Register notice	Applicable 2023-07-28; published 2023-08-04; accessed 2026-06-07	Critical materials for energy include cobalt, dysprosium, neodymium, praseodymium, and terbium; the incorporated USGS critical-minerals list includes samarium.	Government source
R8	DFARS 252.225-7052 restriction on certain magnets, tantalum, and tungsten	Accessed 2026-06-07; rule includes 2027 effective supply-chain expansion	Restrictions for samarium-cobalt and neodymium-iron-boron magnets in covered defense acquisitions, including January 1, 2027 supply-chain scope.	Government acquisition source
R9	ASTM A1102-19 Standard Specification for Sintered Samarium Cobalt Permanent Magnets	Published 2019; abstract accessed 2026-06-07	Standard scope for sintered SmCo permanent magnets, SmCo 1:5 and 2:17 families, and reference to ASTM A977/A977M hysteresisgraph testing.	Standards abstract / full standard may require purchase

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