Blog

Silicon steel properties decide how efficiently a transformer or motor converts power. Add 0.5–4.5% silicon to iron, and resistivity triples. Consequently, eddy current loss drops sharply. At Jiangsu Zhongtong Weiye Special Steel Co., Ltd., we supply both CRGO and CRNGO coil. Here is the technical overview.

Why Silicon Matters

Pure iron has high permeability. However, its low resistivity lets eddy currents heat the core. Silicon raises resistivity. Furthermore, it lowers magnetostriction (noise). Consequently, 3% silicon steel runs cooler and quieter than pure iron.

Two Types, Two Jobs

Type	Grain direction	Best for	Typical grade
CRGO	Along rolling	Transformers	M3, M4, M5
CRNGO	Random	Motors, generators	M19–M43

We supply M3 Grain Oriented Electrical Steel, M4 Grain Oriented Electrical Steel, and M5 Grain Oriented Electrical Steel. Furthermore, we supply M19 Non Oriented Electrical Steel for premium motors.

Production in Five Steps

1. Smelt: carbon below 0.005% via RH degassing.
2. Cast: continuous casting for uniform chemistry.
3. Hot roll: slab to ~2.0 mm coil.
4. Cold roll: high-reduction 20-high mill to 0.23–0.50 mm.
5. Anneal: high-temp atmosphere anneal grows Goss grains.

Furthermore, a phosphate insulation coating goes on last.

Two Key Metrics

Metric	Symbol	What it means
Core loss	P1.5/50	Watts per kg at 1.5 T, 50 Hz
Magnetic induction	B800	Flux density at 800 A/m excitation

Lower core loss = less wasted heat. Higher induction = smaller core.

Where Demand Is Growing

• EV traction motors: 400–1,000 Hz needs 0.15–0.20 mm CRNGO.
• UHV grid: needs premium Hi-B CRGO for long-distance transmission.
• Carbon neutrality: 1% efficiency gain across transformers saves dozens of power plants.

What We Supply

We ship electrical steel coil:

• CRGO: M3, M4, M5.
• CRNGO: M19 and above.
• Thickness: 0.18–0.50 mm.
• Slit to width: ±0.05 mm.
• Coil ID: 508 mm or 406 mm.

Furthermore, we pack for ocean freight with VCI paper.

What We Do Not Do

We do not:

• Produce 6.5% Si ultra-thin strip (mill order).
• Manufacture transformers or motors.
• Supply amorphous metal cores.

Consequently, we are your standard-grade electrical steel coil supplier.

Specify Your Silicon Steel

Tell us:

1. Equipment type (transformer or motor).
2. Operating frequency (Hz).
3. Required core loss (W/kg).
4. Strip width and coil ID.

We will recommend the correct grade and quote.

• Email: vera.liang@ztwysteel.com
• Location: Xishan District, Wuxi, Jiangsu, China
• Supply range: CRGO grain-oriented steel, CRNGO non-oriented steel, slit strip
• Slitting tolerance: ±0.05 mm
• Documentation: MTC with core loss, magnetic induction, thickness, width, and coating

We reply within one working day.