Material 61
also 61
Material 61 is a high-resistivity Ni-Zn ferrite grade with useful permeability from 200 kHz to about 200 MHz, supplied as dry-pressed and sintered cores, beads, sleeves and extruded tubes.
Reference datasheet — Material 61 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the SINT condition
Material 61 tempers and conditions
Material 61 is supplied in one standard condition, SINT. SINT is the default FabDigit quotes; the values on this page are for it.
Supply forms, finishes and certifications
Ways Material 61 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
COAT | Parylene / epoxy-coated cores and beads | Surface finish |
GrD | Diamond-ground / lapped precision cores | Surface finish |
What is Material 61?
Material 61 is a high-resistivity Ni-Zn ferrite grade with useful permeability from 200 kHz to about 200 MHz, supplied as dry-pressed and sintered cores, beads, sleeves and extruded tubes. Engineers choose it for RF chokes and EMI suppression because its high volume resistivity lets windings sit directly on the core; density is 4.7 g/cm3. Limits are a 200 C maximum service temperature and a hard, brittle fired body (machinability 12) that only accepts diamond finishing, so features must be pressed in. For suppression work centred above 25 MHz, Material 43 is the usual alternative. Material 61 has a density of 4.7 g/cm³ (0.17 lb/in³), lighter than 54% of ceramic grades. It melts at 1,550°C (2,822 °F). Material 61 has a tensile strength of 30 MPa (4.35 ksi), weaker than 77% of ceramic grades. Elongation at break is 0% and the elastic modulus is 150 GPa (21.8 Msi).
What is Material 61 used for?
- RF chokes
- EMI suppression beads
- antenna cores
Advantages
- Low embodied carbon — 3.5 kg CO₂/kg, better than 81% of ceramic grades
Limitations
- Limited service temperature — 200°C (392 °F), worse than 84% of ceramic grades
- Hard to polish — 60/100, worse than 79% of ceramic grades
Material 61 properties
Typical room-temperature values for Material 61-SINT; bars are the position among ceramic grades.
Physical3
Material 61 has a density of 4.7 g/cm³ (0.17 lb/in³), lighter than 54% of ceramic grades. It melts at 1,550°C (2,822 °F).
Mechanical11
Material 61 has a tensile strength of 30 MPa (4.35 ksi), weaker than 77% of ceramic grades. Elongation at break is 0% and the elastic modulus is 150 GPa (21.8 Msi).
Thermal5
Material 61 is rated for continuous service to 200°C (392 °F). It conducts heat at 3.9 W/m·K (2.25 BTU/hr·ft·°F), worse than 72% of ceramic grades. Thermal expansion is 8 µm/m·K (4.44 µin/in·°F).
Electrical4
Material 61 has an electrical resistivity of 1,000,000 Ω·m.
Chemical & Environmental2
Corrosion resistance is excellent (85/100), better than 69% of ceramic grades.
Sustainability4
Producing a kilogram of Material 61 takes about 45 MJ of energy and emits 3.5 kg of CO₂ — less than 84% of ceramic grades. Typical recycled content is 10%.
Manufacturability3
Material 61's machinability is not recommended (12/100, better than 78% of ceramic grades).
Common Calculations4
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the ceramic family
Yield strength against density for every ceramic grade FabDigit runs. Material 61 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Material 61
Is Material 61 easy to machine?
Green (unfired) bodies machine easily with carbide; fired 61 requires diamond grinding, slicing or ultrasonic drilling with flood coolant — chipping at edges is the usual reject mode.
Can Material 61 be welded?
Not weldable; assemble by adhesive bonding (epoxy/cyanoacrylate) or mechanical clamping with compliant pads.
Can Material 61 be formed, bent or molded?
Made by spray-dried powder dry-pressing (or extrusion of tubes/beads) then 1180–1320 °C air sintering with ~15–18 % linear shrinkage — allow for shrinkage tolerance in tooling.
Material 61 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| NiOsets Curie point and resistivity | 15 – 24 | 20 |
| ZnOraises permeability, lowers Curie point | 8 – 16 | 11.5 |
| CuOoptional sintering aid | 0 – 2 | 1 |
| CoOoptional loss/temperature-coefficient trim | 0 – 1 | 0.3 |
| Fe2O3spinel host, wt % of oxide blend | ≥ 62 (balance) |
What surface finishes work on Material 61?
Tumble-deburr as-fired parts; parylene or epoxy coating for winding insulation; no plating or anodizing applies, and printed markings need a low-temperature ink.
Equivalent designations
Standards and trade names that resolve to Material 61 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Trade names
- 61
How much does Material 61 cost?
Material 61 is a premium-cost ceramic ($$$), cheaper than about 51% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Material 61 — frequently asked
What is Material 61 used for?
Material 61 is typically used for RF chokes, EMI suppression beads and antenna cores. In short: high-resistivity Ni-Zn ferrite; 200 kHz to 200 MHz; directly wound cores.
What is the tensile strength of Material 61?
Material 61 has a typical tensile strength of 30 MPa (4.35 ksi) — weaker than 77% of ceramic grades.
Is Material 61 easy to machine?
Not especially — machinability is rated not recommended (12/100, better than 78% of ceramic grades). Green (unfired) bodies machine easily with carbide; fired 61 requires diamond grinding, slicing or ultrasonic drilling with flood coolant — chipping at edges is the usual reject mode.
Can Material 61 be welded?
Not weldable; assemble by adhesive bonding (epoxy/cyanoacrylate) or mechanical clamping with compliant pads.
What surface finishes work on Material 61?
Tumble-deburr as-fired parts; parylene or epoxy coating for winding insulation; no plating or anodizing applies, and printed markings need a low-temperature ink.
Can Material 61 be formed, bent or molded?
Made by spray-dried powder dry-pressing (or extrusion of tubes/beads) then 1180–1320 °C air sintering with ~15–18 % linear shrinkage — allow for shrinkage tolerance in tooling.
What is the maximum service temperature of Material 61?
Material 61 is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does Material 61 cost?
Material 61 is a premium-cost ceramic ($$$), cheaper than about 51% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- 61 Material Data Sheet (NiZn ferrite, µi = 125) — Fair-Rite Products Corp. (2023)
- ASM Engineered Materials Handbook Vol. 4 — Ceramics and Glasses (soft ferrites) — ASM International (1991)
- Soft Ferrites: Properties and Applications — Butterworth-Heinemann (E.C. Snelling) (1988)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.