B27R090 0.27mm Slit Coil Electrical Steel for Transformer

 

B27R090 is a premium laser-domain-refined cold-rolled grain-oriented (CRGO) electrical steel - also widely called silicon steel or transformer steel - with a fixed nominal thickness of 0.27 mm. Slit coils are full-width master coils processed into narrow customized strips on precision slitting lines, directly ready for transformer core stacking without further cutting by the manufacturer.

 

 

As an iron-silicon soft magnetic alloy with a silicon content typically 2.9%–3.5% (Hi-B grades ≈ 3.2%), B27R090 is engineered with a sharp Goss texture (uniform grain orientation) and laser domain refinement to minimize energy loss in electromagnetic equipment. Unlike galvanized structural steel coils, this grade is used exclusively for magnetic core production - a key raw material for energy-efficient power transformers, distribution transformers and large reactors.

 

GNEE Steel, a professional electrical steel supplier with 18+ years of export experience, provides finished B27R090 slit coils with slit edge / mill edge options, C-2 type insulation coating and full third-party inspection certificates, serving transformer factories across Southeast Asia, the EU, the Middle East, Africa and South America.

 

Each character follows the Baosteel domestic CRGO designation system, helping global buyers identify performance parameters at a glance:

• B - Original manufacturer brand code (Baosteel, one of China's top silicon steel mills)
• 27 - Nominal thickness = 0.27 mm
• R - Laser domain-refined, high magnetic induction grain-oriented silicon steel series
• 090 - Maximum allowable core loss P17/50 ≤ 0.90 W/kg (test condition: 1.7 T magnetic flux density, 50 Hz)

 

 

Electromagnetic Performance

(Per GB/T 2521 - current edition - and IEC 60404-8-7; guarantee values subject to the governing standard edition and the mill test certificate.)

Parameter	Standard Value of B27R090
Nominal Thickness	0.27 mm
Theoretical Density	7.65 kg/dm³
Max Core Loss P17/50 (1.7 T, 50 Hz)	≤ 0.90 W/kg
Min Magnetic Induction B800 (800 A/m)	≥ 1.87 T
Surface Insulation Coating	C-2 type (inorganic, forsterite-based) insulation coating

 

Mechanical Properties

(Typical test data, rolling direction, per GB/T 228.1-2021 and GB/T 2521; informational - not acceptance criteria.)

Mechanical Index (L - rolling direction)	Typical Data
Tensile Strength	≈ 355 N/mm²
Yield Strength	≈ 330 N/mm²
Elongation	≈ 10%
Hardness	≈ 200 HV
Bending (transverse)	≥ 2 times per GB/T 2521; typical 3–5 times
Stacking Factor	≥ 97% per GB/T 2521 (typical ≈ 97.5% for burr-free slit coils)

 

Slit Coil General Dimensions 

• Master coil width: 900–1250 mm

• Slitted finished width: 20–1200 mm (custom slit edge)

• Single coil weight: 5–14 tons

• Inner coil diameter: 508 mm (610 mm available on request)

• Surface coating: C-2 type anti-rust insulation film; light-oiled surface optional

• Compliance standards: GB/T 2521, IEC 60404-8-7, ASTM A876, JIS C2553, EN 10107

• Certifications: ISO 9001, RoHS, REACH; BIS/ISI certification available for India-bound shipments (as applicable)

 

 

 

Ultra-Low Core Loss & Energy Saving

The P17/50 core loss capped at 0.90 W/kg minimizes heat generation and power waste during transformer operation. For grid distribution transformers, B27R090 reduces long-term operating losses compared with conventional non-domain-refined grades, fully supporting global energy-efficiency requirements for power equipment.

 

High Magnetic Induction & Compact Core Design

Minimum magnetic induction B800 ≥ 1.87 T delivers stronger magnetic flux under rated excitation. Transformer manufacturers can downsize the core, save on silicon steel and copper winding cost, and lower overall equipment weight.

 

Low Magnetostriction, Reduced Noise & Vibration

Laser domain refinement suppresses irregular domain-wall movement, significantly reducing magnetostriction noise. B27R090 is suitable for large power transformers with strict acoustic noise requirements, helping solve noise concerns for urban grid substations.

 

Superior Processing Performance for Slitting & Stamping

Uniform thickness, ultra-flat surface and consistent mechanical performance support high-speed slitting, blanking and punching with low edge-cracking risk. GNEE's precision slitting line produces burr-minimized slit edges, improving stacking factor and core assembly efficiency.

 

Stable Coating & Anti-Corrosion Performance

The standard C-2 type insulation coating offers strong adhesion, heat resistance and chemical resistance, preventing oxidation during storage and coil handling.

 

 

Most transformer factories require narrow-width strips instead of full-width master coils. GNEE provides one-stop slitting processing for B27R090 raw CRGO coils:

• Custom slitting width from 20 mm to 1200 mm, tolerance ±0.1 mm
• Two edge options: clean slit edge / original mill edge
• Adjustable coil weight to match customer production-line capacity
• Secondary surface treatment: re-oiling, re-insulation coating on demand
• Cut-to-length sheet processing available in addition to slit coils

 

Free lab test samples (50–200 kg, freight collect); production trial orders generally from 1–2 t - confirm MOQ with your sales engineer; bulk order monthly supply capacity: several thousand metric tons of electrical steel, subject to mill allocation and grade availability

 

 

B27R090 is used for electromagnetic core manufacture in the following fields:

• Power Transmission Transformers: large UHV power grid transformers, converter transformers for hydropower & renewable-energy power stations
• Distribution Transformers: residential, commercial and industrial grid distribution transformers (10 kV–35 kV)
• Reactors & Inductors: power compensation reactors, saturable reactors, smoothing reactors for HVDC converter stations
• Instrument Transformers: current and voltage transformers (CT/VT) for metering and protection
• Special Magnetic Cores: welding-machine magnetic cores and other silicon-steel-laminated cores where grain-oriented material is specified

 

For international buyers switching from foreign brands, B27R090 corresponds approximately to the following mainstream grades:

Mill / Region	Approx. Equivalent Grade
Nippon Steel (Japan)	27ZH090 / 27ZSH090 series
JFE Steel (Japan)	27JGD090 series
POSCO (South Korea)	27PM090 / 27PN090 series
Cleveland-Cliffs / AK Steel (USA)	27H090
ThyssenKrupp (Germany)	27PH090

 

 

As an authorized cooperative distributor of Baosteel, Wuhan Iron & Steel (Baowu Group), Shougang and JISCO - top Chinese silicon steel mills - GNEE implements full-process quality inspection for all B27R090 slit coils:

• Raw material incoming test: electromagnetic performance lab testing for each master coil batch
• Slitting process inspection: real-time monitoring of width tolerance, edge burr and surface flatness
• Finished coil sampling: random core loss & magnetic induction re-test before shipment
• Full documentation: mill test certificate (MTC), ISO 9001, RoHS/REACH declarations, third-party inspection reports
• Batch traceability: each coil marked with heat number, grade, weight and production date for quality tracking

 

 

 

Packaging Standard seaworthy export packing: waterproof plastic film + metal strapping + wooden pallet, with anti-rust paper wrapped inside to protect against sea-moisture corrosion during long ocean transit.

 

Delivery Time

• Bulk slit coil orders: 30 days after deposit confirmation
• Small sample orders: 7–10 days quick delivery

 

Shipping Terms FOB Shanghai / Tianjin port; CIF and CFR door-to-door delivery available upon request.

 

Price Model Tiered wholesale pricing based on order weight:

• 2,000–9,999 kg: standard unit price
• 10,000 kg and above: discounted bulk factory price

 

 

Q1: What is the difference between B27R090 and B27G120 electrical steel?

A: B27R090 is a laser-domain-refined high-induction grade with lower core loss (P17/50 ≤ 0.90 W/kg), suited to high-efficiency large transformers; B27G120 is a conventional general-purpose CRGO grade with higher core loss, used for cost-sensitive small distribution transformers. (Confirm the current Baosteel product list for exact G-series limits.)

 

Q2: Can GNEE provide free B27R090 test samples?

A: Yes - we support small sample coils (50–200 kg) for your lab performance testing; buyers only bear the freight cost. Production trial orders are generally from 1–2 t; please confirm the MOQ with your sales engineer.

 

Q3: Is B27R090 slit coil suitable for solar (PV) transformer cores?

A: Yes. Its low loss and low noise performance suit photovoltaic grid-connected transformer design requirements, and it is widely adopted by solar equipment manufacturers.

 

Q4: Which edge finish is better for core stacking - slit edge or mill edge?

A: Burr-minimized slit edge delivers a higher stacking factor (typically ≈97.5%) and is recommended for high-precision, high-efficiency transformer production; mill edge is a cost-effective option for general-purpose transformers.

 

Get Free Datasheet & Factory Quotation

If you are a transformer manufacturer, electrical equipment wholesaler or core laminator looking for a stable supply of B27R090 0.27mm slit CRGO electrical steel coils, GNEE Steel can offer:

✅ Full technical datasheet with magnetization (B-H) curve & mechanical test data

✅ Custom slit width solution and drawing support

✅ Competitive ex-factory bulk price with long-term contract discounts

✅ Complete export certification documents for customs clearance

✅ Professional technical support for core design and application selection (including non-oriented grades for rotating machines)

Send your inquiry now

 

Send your inquiry now via our website contact form - include your required slit width, order tonnage and target application - and our electrical steel sales engineer will reply within 24 hours with a detailed quotation and technical parameters.

 

---

All performance data refer to the applicable standard edition (GB/T 2521, IEC 60404-8-7) and the mill test certificate at the time of ordering; approximate equivalent grades are for reference only and must be verified against each mill's current datasheet. The MTC and the formal quotation shall prevail.