Comprehensive Industry Knowledge: SD-Core Magnetic Cores
1. SD-Core Overview
SD-Core (SD-Type Magnetic Core) is a high-performance, split magnetic component manufactured from grain-oriented silicon steel strips. Its unique double-loop "S" profile, formed by two interlocking half-cores, creates a closed magnetic circuit with exceptional structural rigidity and magnetic efficiency.
Designed for ultra-low core loss, high magnetic permeability, and precise air gap control, SD-Cores are widely used in high-efficiency transformers, power inductors, UPS systems, and industrial power supplies. Their robust design and consistent performance make them ideal for both 50Hz power distribution and 400Hz aerospace/industrial applications.
2. Translated Technical Parameters (From Product Brochure)
(A) 50Hz HSD Series Parameters
| Core Model | Dimensions (mm) a × b × c × h | Output Power (VA) 50Hz | Core Weight (kg) |
|---|---|---|---|
| HSD10×20×20 | 10 × 20 × 12.5 × 20 | 2.55 | 0.250 |
| HSD10×20×25 | 10 × 20 × 12.5 × 25 | 3.69 | 0.270 |
| HSD10×20×32 | 10 × 20 × 12.5 × 32 | 5.55 | 0.300 |
| HSD10×20×40 | 10 × 20 × 12.5 × 40 | 7.36 | 0.340 |
| HSD12.5×25×25 | 12.5 × 25 × 16 × 25 | 13.90 | 0.480 |
| HSD12.5×20×32 | 12.5 × 25 × 16 × 32 | 20.10 | 0.520 |
| HSD12.5×20×40 | 12.5 × 25 × 16 × 40 | 28.40 | 0.590 |
| HSD12.5×20×50 | 12.5 × 25 × 16 × 50 | 35.40 | 0.660 |
| HSD16×32×32 | 16 × 32 × 20 × 32 | 47.20 | 1.000 |
| HSD16×32×40 | 16 × 32 × 20 × 40 | 67.70 | 1.100 |
| HSD16×32×50 | 16 × 32 × 20 × 50 | 93.40 | 1.210 |
| HSD16×32×64 | 16 × 32 × 20 × 64 | 127.00 | 1.380 |
| HSD20×32×40 | 20 × 32 × 25 × 40 | 143.00 | 1.570 |
| HSD20×32×50 | 20 × 32 × 25 × 50 | 184.00 | 1.720 |
| HSD20×32×64 | 20 × 32 × 25 × 64 | 225.00 | 1.920 |
| HSD20×32×80 | 20 × 32 × 25 × 80 | 281.00 | 2.500 |
| HSD25×40×50 | 25 × 40 × 32 × 50 | 302.00 | 3.050 |
| HSD25×40×64 | 25 × 40 × 32 × 64 | 370.00 | 3.410 |
| HSD25×40×80 | 25 × 40 × 32 × 80 | 457.00 | 3.770 |
| HSD25×40×100 | 25 × 40 × 32 × 100 | 556.00 | 4.260 |
| HSD32×50×64 | 32 × 50 × 40 × 64 | 720.00 | 6.280 |
| HSD32×50×80 | 32 × 50 × 40 × 80 | 839.00 | 7.038 |
| HSD32×50×100 | 32 × 50 × 40 × 100 | 1038.00 | 7.580 |
| HSD32×50×125 | 32 × 50 × 40 × 125 | 1275.00 | 8.510 |
| HSD40×64×80 | 40 × 64 × 50 × 80 | 1800.00 | 12.560 |
| HSD40×64×100 | 40 × 64 × 50 × 100 | 1963.00 | 13.730 |
| HSD40×64×125 | 40 × 64 × 50 × 125 | 2396.00 | 15.190 |
| HSD40×64×160 | 40 × 64 × 50 × 160 | 3006.00 | 17.230 |
| HSD50×80×100 | 50 × 80 × 64 × 100 | 3550.00 | 24.720 |
| HSD50×80×125 | 50 × 80 × 64 × 125 | 4283.00 | 27.000 |
| HSD50×80×160 | 50 × 80 × 64 × 160 | 5298.00 | 30.190 |
| HSD50×80×200 | 50 × 80 × 64 × 200 | 6366.00 | 33.840 |
(B) 400Hz BSD Series Parameters
| Core Model | Dimensions (mm) a × b × c × h | Output Power (VA) 400Hz | Core Weight (kg) |
|---|---|---|---|
| BSD8×12.5×16 | 8 × 12.5 × 10 × 16 | 22.00 | 0.100 |
| BSD8×12.5×20 | 8 × 12.5 × 10 × 20 | 35.00 | 0.110 |
| BSD8×12.5×32 | 8 × 12.5 × 10 × 32 | 55.50 | 0.120 |
| BSD8×12.5×40 | 8 × 12.5 × 10 × 40 | 68.20 | 0.130 |
| BSD10×12.5×20 | 10 × 12.5 × 12.5 × 20 | 67.30 | 0.150 |
| BSD10×12.5×25 | 10 × 12.5 × 12.5 × 25 | 82.60 | 0.170 |
| BSD10×12.5×32 | 10 × 12.5 × 12.5 × 32 | 109.00 | 0.180 |
| BSD10×12.5×40 | 10 × 12.5 × 12.5 × 40 | 135.00 | 0.210 |
| BSD12.5×12.5×25 | 12.5 × 12.5 × 16 × 25 | 123.00 | 0.240 |
| BSD12.5×12.5×32 | 12.5 × 12.5 × 16 × 32 | 150.00 | 0.270 |
| BSD12.5×12.5×40 | 12.5 × 12.5 × 16 × 40 | 183.00 | 0.290 |
| BSD12.5×12.5×50 | 12.5 × 12.5 × 16 × 50 | 231.00 | 0.330 |
| BSD16×16×32 | 16 × 16 × 20 × 32 | 253.00 | 0.500 |
| BSD16×16×40 | 16 × 16 × 20 × 40 | 301.00 | 0.550 |
| BSD16×16×50 | 16 × 16 × 20 × 50 | 382.00 | 0.610 |
| BSD16×16×64 | 16 × 16 × 20 × 64 | 488.00 | 0.690 |
| BSD20×20×40 | 20 × 20 × 25 × 40 | 498.00 | 0.980 |
| BSD20×20×50 | 20 × 20 × 25 × 50 | 614.00 | 1.070 |
| BSD20×20×64 | 20 × 20 × 25 × 64 | 744.00 | 1.200 |
| BSD20×20×80 | 20 × 20 × 25 × 80 | 891.00 | 1.350 |
| BSD25×25×52 | 25 × 25 × 32 × 50 | 869.00 | 1.930 |
| BSD25×25×64 | 25 × 25 × 32 × 64 | 1088.00 | 2.130 |
| BSD25×25×80 | 25 × 25 × 32 × 80 | 1343.00 | 2.360 |
| BSD25×25×100 | 25 × 25 × 32 × 100 | 1616.00 | 2.640 |
| BSD32×32×80 | 32 × 32 × 40 × 80 | 1986.00 | 4.020 |
| BSD32×32×100 | 32 × 32 × 40 × 100 | 2458.00 | 4.360 |
| BSD32×32×125 | 32 × 32 × 40 × 125 | 2996.00 | 4.860 |
| BSD40×40×80 | 40 × 40 × 50 × 80 | 3314.00 | 7.850 |
| BSD40×40×100 | 40 × 40 × 50 × 100 | 4064.00 | 8.580 |
| BSD40×40×125 | 40 × 40 × 50 × 125 | 4849.00 | 9.490 |
| BSD40×40×160 | 40 × 40 × 50 × 160 | 6329.00 | 10.770 |
3. Production Process of SD-Cores
The manufacturing of SD-Cores requires exceptional precision to maintain their unique interlocking geometry and magnetic performance:
Raw Material Selection: Premium grain-oriented silicon steel strips (0.23–0.35mm thickness) are selected for ultra-low core loss and high permeability.
Precision Slitting & Cutting: Strips are slit to exact widths and cut to length, with tolerances held to ±0.03mm to ensure perfect alignment during assembly.
Specialized Winding: Automated winding machines form the complex "S" half-core profiles, maintaining uniform stacking tension to eliminate internal gaps.
High-Temperature Annealing: Cores are annealed in a nitrogen atmosphere to relieve stress and enhance magnetic properties, with strict temperature control (800–1000°C).
Insulation Coating: A high-temperature, scratch-resistant insulating varnish is applied to prevent inter-lamination shorts and improve durability.
Interlocking Assembly: The two half-cores are precisely mated using a guided alignment system, ensuring seamless magnetic contact. Air gaps are adjusted to specifications.
Multi-Stage Testing: Each core undergoes inductance, core loss, saturation, and mechanical integrity testing to verify performance.
Final Inspection: Visual, dimensional, and electrical checks confirm compliance with standards before packaging.
4. Packaging & Transportation
Packaging
Inner Protection: Each core is individually wrapped in anti-static foam or bubble wrap to prevent scratches and impact damage. Larger cores are fitted with custom plastic end caps to protect critical mating surfaces.
Outer Packaging: Sturdy double-walled corrugated cartons with foam dividers hold cores securely, clearly labeled with model, quantity, and handling instructions.
Moisture Control: Desiccant packets and anti-rust VCI paper are included to prevent oxidation, especially for sea freight shipments.
Customization: OEM/ODM packaging with customer logos, barcodes, and custom foam inserts is available upon request.
Transportation
Shipping Options:
Air freight for urgent 400Hz aerospace/industrial orders.
Sea freight for bulk 50Hz power core shipments (cost-effective, 20–45 day lead times).
Courier services (DHL/FedEx) for samples or small batches.
Handling Notes: Avoid dropping or stacking heavy loads. Store in a dry, temperature-controlled environment (15–30°C) away from strong magnetic fields. Special care must be taken to protect the mating surfaces from damage.
5. Advantages & Disadvantages of SD-Cores
✅ Advantages
Ultra-Low Core Loss: The interlocking design minimizes magnetic flux leakage, resulting in significantly lower core loss compared to conventional EI/ED cores.
Superior Mechanical Stability: The "S" profile creates a rigid, self-locking structure that resists deformation under high winding tension or mechanical stress.
Precise Air Gap Control: The split design allows for highly accurate air gap adjustment, making SD-Cores ideal for applications requiring stable inductance and saturation resistance.
High Power Density: High permeability and low loss enable smaller, lighter core designs for the same power rating, perfect for compact power supplies.
Broad Frequency Compatibility: Available in both 50Hz (HSD) and 400Hz (BSD) variants, suitable for power distribution and aerospace applications.
❌ Disadvantages
Higher Manufacturing Cost: The complex winding and assembly process makes SD-Cores more expensive than standard EI cores.
Alignment Sensitivity: The interlocking design requires extremely precise mating; even minor misalignment can degrade magnetic performance.
Specialized Winding Requirements: The double-loop geometry requires custom winding tools, which can increase production complexity for customers.
Limited Availability: Due to their specialized nature, SD-Cores may have longer lead times compared to more common core types.
6. Frequently Asked Questions (FAQ)
Q1: What are the primary applications of SD-Cores?A: SD-Cores are used in high-efficiency power transformers, industrial UPS systems, aerospace 400Hz power supplies, high-frequency inductors, and renewable energy inverters. They excel in applications requiring low loss, high stability, and compact design.
Q2: How do I select the right SD-Core model?A: Choose based on three key factors:
Rated power (VA) and operating frequency (50Hz/400Hz).
Physical dimensions (a × b × c × h) to fit your device's form factor.
Core weight and loss characteristics for efficiency requirements. Contact our engineering team for custom recommendations.
Q3: Can SD-Cores be customized?A: Yes. We offer custom SD-Cores with tailored dimensions, air gaps, and coatings to meet unique application needs. Custom orders typically take 4–6 weeks for production.
Q4: What is the difference between HSD (50Hz) and BSD (400Hz) series?A: HSD cores are optimized for low-frequency power distribution (50Hz), while BSD cores are designed for high-frequency applications (400Hz) common in aerospace and industrial power systems. They differ in core loss characteristics and winding design.
Q5: How should I store SD-Cores to prevent degradation?A: Store cores in a dry, temperature-controlled environment (15–30°C) away from moisture and strong magnetic fields. Avoid prolonged storage exceeding 24 months to prevent oxidation.