Table of Contents
Why SinterWorks for Soft Magnetic PM Components
We manufacture motor cores, pole pieces, solenoid hardware, and actuator components where magnetic performance and net-shape economics matter at volume.
- FC-0000 soft iron and SMC material routes for motor and solenoid programs
- EV and appliance motor program experience including rotor and stator concepts
- Secondary machining for critical air-gap and mounting features when needed
- Magnetic PM feasibility review within 24–48 hours
Typical Soft Magnetic PM Targets
| Feature | Typical Value | Notes |
|---|---|---|
| Materials | FC-0000, SMC composites | Frequency and flux density dependent |
| Applications | Motors, solenoids, actuators | EV, appliance, industrial |
| Design freedom | 3D magnetic geometry | Advantage vs laminated stacks |
| Tolerance strategy | Sizing on critical faces | Air-gap features may need machining |
| Economical volume | 10,000+ pcs/year | Tooling improves magnetic repeatability |
| Sample lead time | 2–4 weeks | After magnetic target confirmation |
Related Material & Proof Pages
Related Application Pages
Design Notes for Magnetic PM Parts
- Share target flux density, frequency, and operating temperature before material selection.
- Define air-gap and stack-up tolerances that affect magnetic performance.
- Consider SMC when 3D magnetic geometry or high-frequency response is required.
- Plan validation testing early when converting from laminated or machined magnetic parts.
Need soft magnetic PM components?
Send your drawing, permeability or flux targets, and annual volume for material selection and PM feasibility review.
Introduction
Soft magnetic powder metallurgy components convert electrical energy to mechanical force or detect magnetic fields. They are core components in electric motors, solenoids, sensors, and actuators — applications where magnetic performance, dimensional precision, and production repeatability all matter.
PM produces soft magnetic components through the same press-and-sinter process used for structural parts, but the material selection and processing focus on magnetic properties: permeability, saturation flux density, and core loss (iron loss).
If you are sourcing soft magnetic components, request a quote or DFM review with part drawings and magnetic requirements.
Soft Magnetic PM Products
FC-0000 Soft Iron Components
FC-0000 is a pure iron PM grade — no alloying additions — with high magnetic permeability and low coercivity. It is the baseline material for soft magnetic PM applications.
Key magnetic properties (sintered, uncoated):
- Maximum permeability: 1,500–2,500 μ relative
- Saturation flux density: 1.9–2.1 T
- Coercivity: 95–150 A/m
Typical applications:
- Solenoid cores and pole pieces
- Magnetic sensor housings (ABS tone rings, speed sensors)
- Relay armatures and yokes
- VVT stator and rotor assemblies
- Electromagnetic actuator cores
Limitation: FC-0000 has higher iron losses at elevated frequency (above ~200 Hz) compared to laminated steel or SMC materials.
See the FC-0000 Material Guide for detailed property data.
Soft Magnetic Composites (SMC)
Soft magnetic composites are iron powder particles individually coated with an insulating layer, then compacted at high pressure and cured. The insulation breaks the eddy current paths between particles, dramatically reducing iron losses at higher frequencies.
Key SMC advantages over FC-0000:
- 3D magnetic flux — isotropic permeability (useful for complex 3D motor geometries)
- Lower core losses at 100–1,000 Hz
- Complex 3D shapes achievable in a single compaction step
Key SMC tradeoffs:
- Permeability is lower than laminated steel at low frequency
- Mechanical strength is lower than structural PM grades
- Not suitable for applications requiring >5 MPa tensile stress
Typical SMC applications:
- Axial flux motor stators
- Transverse flux motor cores
- High-frequency inductor cores
- Claw pole alternator stators
See the Soft Magnetic Composites Material Guide for property data and design notes.
ABS Sensor Rings and Tone Wheels
ABS sensor rings (tone wheels) are sintered FC-0000 or low-alloy iron rings with precisely spaced teeth or slots. They generate the alternating magnetic signal read by the wheel speed sensor.
Design requirements:
- Consistent pole pitch (tooth-to-slot ratio)
- Surface runout: typically <0.1 mm TIR
- Material: FC-0000 or equivalent for adequate permeability and consistent signal generation
See the ABS Sensor Rings Application Page for detailed application notes.
VVT Stator and Rotor Assemblies
Variable valve timing (VVT) phaser stators and rotors are a high-volume automotive PM application. The stator provides the housing and the rotor positions the phaser under hydraulic and magnetic control.
Requirements:
- Dimensional consistency for hydraulic sealing
- Magnetic properties supporting valve timing signal detection
- Material: FC-0000 or low-alloy iron
See the VVT Stator and Rotor Application Page for more detail.
Design Guidance for Soft Magnetic PM Parts
Key Design Rules
- Keep wall thickness above 2 mm for structural integrity during compaction and handling
- Avoid sharp internal corners — radius of at least 0.5 mm reduces stress concentration and die wear
- Align complex features with press direction — features perpendicular to compaction require secondary operations
- Specify magnetic properties, not just material grade — permeability and saturation flux density must be verified, not assumed from chemistry alone
Testing and Verification
Soft magnetic PM parts require magnetic testing in addition to standard dimensional and mechanical inspection:
- DC permeability testing (low-frequency permeameter)
- AC core loss measurement (if operating at elevated frequency)
- Saturation flux density verification (important for motor design)
Our quality process includes dimensional inspection and first-article documentation. Magnetic property testing is available through partner test laboratories; we coordinate on request.
Material Comparison: FC-0000 vs SMC vs Laminated Steel
| Property | FC-0000 PM | SMC | Laminated Silicon Steel |
|---|---|---|---|
| Relative permeability | 1,500–2,500 | 200–500 | 3,000–10,000 |
| Saturation flux density | 1.9–2.1 T | 1.5–1.8 T | 1.5–2.0 T |
| Core loss at 400 Hz | High | Low | Medium |
| 3D flux capability | No (2D) | Yes | No (2D) |
| Shape complexity | High | High | Low (2D only) |
| Mechanical strength | Moderate | Low | High |
| Cost per part at volume | Low–Medium | Medium | Depends on lamination complexity |
Applications by Industry
Automotive: ABS sensor rings, VVT stators/rotors, solenoid valve cores, brushless DC motor stators.
Industrial machinery: Relay components, proximity sensor housings, solenoid actuators, lifting magnet poles.
Consumer electronics: Small motor cores, haptic actuator components, magnetic encoder wheels.
Power tools and appliances: DC motor stators, brushless motor cores for cordless tool drivetrains.
See also: Electric Motor Components.
Frequently Asked Questions
What is the difference between soft magnetic PM and structural PM?
Structural PM uses alloying elements (copper, nickel, carbon) to increase mechanical strength. Soft magnetic PM uses pure or very low alloy iron to maximize magnetic permeability and minimize coercivity. Adding carbon or nickel for strength degrades magnetic properties significantly.
Can sintered soft magnetic parts replace laminated steel?
For low-frequency applications (below 100 Hz), FC-0000 PM parts are a practical alternative to laminations, especially when the part geometry would be expensive to stamp and stack. At higher frequencies, SMC is a better PM option. Laminated silicon steel generally has higher permeability and lower core loss than PM at any frequency.
What tolerances can be held on soft magnetic PM parts?
As-sintered tolerances are typically ±0.10–0.20 mm. After sizing (a secondary compaction step), key dimensions can be held to ±0.025–0.05 mm. For surfaces requiring tight runout, grinding is used.
Do soft magnetic PM parts need surface treatment?
Bare sintered iron has adequate corrosion resistance for oil-immersed environments (gearbox, hydraulic). For exposed environments, zinc phosphate, steam treatment, or zinc plating are common. Plating must be evaluated for dimensional impact on magnetic air gaps.
What is the minimum order quantity for soft magnetic PM components?
Typical production batch sizes are 1,000–50,000 pieces depending on part size. Tooling cost is fixed; larger batches reduce per-part cost. Contact us for specific MOQ guidance based on part size and complexity.
Related Resources
Use these internal links to keep moving through the most relevant guides, service pages, and technical references for this topic.
FC-0000 Soft Iron Material
Detailed magnetic and mechanical property data for pure iron PM grade.
Soft Magnetic Composites
SMC material properties and design notes for high-frequency motor and actuator applications.
Electric Motor Components
PM in brushless motor, solenoid, and actuator programs.
Request a Quote
Send your part drawing and magnetic requirements for review and quotation.
Need Soft Magnetic PM Components?
Share your part drawing, magnetic requirements (permeability, flux density), and annual volume. We can help select material and assess PM feasibility for your motor or sensor application.
- DFM review support
- Material and process guidance
- Quotation feedback within 24-48 hours