A27QG090K 0.27mm, 0.90 W/Kg HiB Grain-Oriented Silicon Steel
Aug 25, 2026
Leave a message
A27QG090K is one such grade: a high-magnetic-induction (HiB) cold-rolled grain-oriented (CRGO) silicon steel supplied at 0.27 mm nominal thickness with a guaranteed core loss of 0.90 W/kg (P1.7/50).
This article consolidates the grade's technical profile, mechanical and magnetic behavior, and its role in transformer core manufacturing, and is intended as a reference for design engineers, procurement specialists, and transformer OEMs.
What Is A27QG090K Grain-Oriented Silicon Steel?
A27QG090K belongs to the family of high-magnetic-induction grain-oriented silicon steel (HiB, also written as High-B or high-permeability GO). The designation follows the conventional grain-oriented coding scheme:
- A - manufacturer prefix (mill-specific brand code)
- 27 - nominal thickness of 0.27 mm (thickness × 100)
- QG - Quasi-Grain / high-magnetic-induction oriented silicon steel, the premium subclass of CRGO with superior magnetic induction
- 090 - maximum specific core loss of 0.90 W/kg at 1.7 T and 50 Hz (P1.7/50 × 100)
- K - coating / treatment suffix defined by the producing mill
Grain-oriented silicon steel is produced so that its cube-on-edge texture is strongly aligned with the rolling direction, giving extremely low core loss and high permeability along that axis. The QG (HiB) subclass achieves this through a secondary recrystallization process that yields both lower iron loss and higher magnetic induction than conventional CGO grades, which is why A27QG090K is favored in energy-efficient transformers.
Key Takeaways
- A27QG090K is a premium high‑magnetic‑induction (Hi‑B) CRGO silicon‑steel grade, nominal thickness 0.27 mm, guaranteed maximum core loss ≤0.90 W/kg at P1.7/50, B8 ≥ 1.88 T.
- Code breakdown: 27 = 0.27 mm, QG = high‑induction grain‑oriented steel, 090 = 0.90 W/kg loss limit; prefix A and suffix K are mill‑specific brand and insulation‑coating identifiers.
- Compared with conventional CGO silicon steel, its optimized Goss texture delivers lower iron loss and higher magnetic induction, suitable for Tier‑1 high‑efficiency distribution transformers, large‑scale power transformers and reactors.
- 0.27 mm thin gauge cuts eddy‑current loss. The inorganic stress‑relief coating reduces core loss further. The material supports laser scribing domain refinement for extra‑low‑loss performance. Always cross‑check final parameters against official mill test certificates before substitution.
Technical Specifications of A27QG090K
The values below represent typical datasheet limits for a 0.27 mm HiB CRGO grade of this classification. Always confirm against the actual mill test certificate, as manufacturer-specific "A" and "K" codes may carry slight deviations.
| Property | Typical Value / Limit | Note |
|---|---|---|
| Grade | A27QG090K | HiB grain-oriented electrical steel |
| Material type | Cold Rolled Grain-Oriented (CRGO), HiB | High magnetic induction |
| Nominal thickness | 0.27 mm | Thin gauge for low loss |
| Core loss P1.7/50 | ≤ 0.90 W/kg | At 1.7 T, 50 Hz |
| Core loss P1.7/60 | ≤ 1.10 W/kg (typical) | At 1.7 T, 60 Hz |
| Magnetic induction B8 | ≥ 1.88 T | At H = 800 A/m |
| Silicon content | 2.9 – 3.3 % | Typical for oriented grades |
| Density | ~ 7.65 g/cm³ | For mass/stack calculations |
| Stacking factor | ≥ 0.96 | Depends on coating thickness |
| Coating | Inorganic insulation / stress coating (K-suffix) | Mill-defined code |
| Edge condition | Mill Edge (ME) / Slit Edge (SE) | Per slitting requirement |
| Supply form | Coil, slit coil, cut-to-length sheet, strips | Transformer lamination input |
| Standards | GB/T 2521; IEC 60404-8-7; ASTM A876 | Equivalent grade frameworks |
Request a Quote for A27QG090K
Planning to source 0.27 mm HiB CRGO for your transformer cores? Send GNEE Steel your required width, coating, edge condition and quantity - we return a competitive quote with lead time, typically within 24 hours.
Or email your specifications to sales@gneesteels.com
Magnetic Properties and Performance
The defining advantage of the QG / HiB subclass is that it delivers higher magnetic induction at the same field and lower core loss at the same flux density compared with conventional CGO (e.g. CGOG-class) materials.
For A27QG090K:
- B8 ≥ 1.88 T means the core can be run at higher flux density without saturating, allowing smaller, lighter transformers or higher power rating in the same footprint.
- P1.7/50 ≤ 0.90 W/kg directly reduces no-load (iron) loss - the dominant loss component in continuously energized distribution and power transformers.
The strong Goss texture minimizes domain-wall pinning, which is why the grade also tolerates laser/plasma domain-refinement treatments when further loss reduction is required.
In practice, a 0.27 mm HiB grade sitting at 0.90 W/kg is positioned in the high-efficiency band used for Tier-1 / high-efficiency distribution transformers and medium-to-large power transformers where no-load loss limits are stringent.
Why 0.27mm Thickness and 0.90 W/kg Core Loss Matter
Core loss in grain-oriented steel has two components: hysteresis loss (material/texture dependent) and eddy-current loss (proportional to thickness squared). Reducing gauge from 0.30 mm to 0.27 mm lowers eddy-current loss, while the HiB texture suppresses hysteresis loss. The combined effect is the 0.90 W/kg figure in this grade.
For the end user, this translates into:
- Lower lifetime energy cost of the transformer
- Compliance with eco-design and efficiency regulations (e.g. high-efficiency distribution transformer mandates)
- Reduced heat generation and improved thermal margin
Applications of A27QG090K in Power Transformers
A27QG090K is engineered for stacked and wound transformer cores where low no-load loss is critical:
- Power transformers - large grid and substation units (including EHV/UHV classes)
- Distribution transformers - pole-mounted and pad-mounted, high-efficiency distribution
- Oil-immersed and dry-type transformers
- Transformer cores - stacked cores, wound (toroidal/rectangular) cores, laminated iron cores
- Reactors - shunt, series, and smoothing reactors where low-loss magnetic paths are needed
Coating, Edge and Supply Forms
The K suffix denotes the mill-specific coating system applied to A27QG090K. Oriented grades are finished with an inorganic, glass-like stress coating that (a) provides inter-laminar insulation to suppress eddy currents and (b) applies a beneficial tensile stress that further reduces core loss. Typical edge conditions available are Mill Edge (ME), Slit Edge (SE), and deburred/trimmed edges depending on the slitting line and customer specification.
GNEE Steel supplies A27QG090K in coils, slit coils, cut-to-length sheets, and narrow strips, with edge and coating matched to the customer's core-manufacturing process.
Why Source A27QG090K from GNEE Steel
GNEE Steel provides A27QG090K and a full range of grain-oriented and non-oriented electrical steels with mill test certificates, thickness and core-loss verification, and slitting/cut-to-length services. Our supply covers the common 0.18–0.35 mm HiB CRGO band and supports transformer, reactor, and motor-core manufacturers worldwide.
- Grade verification against EN/IEC/GB standards
- Slitting to required widths with controlled edge burr
- Stable thickness and coating for automated stacking lines
- Global export documentation and logistics support
Conclusion
A27QG090K combines a thin 0.27 mm gauge with a 0.90 W/kg core-loss guarantee in a high-magnetic-induction grain-oriented steel, making it a strong choice for efficiency-critical transformer cores. For datasheets, pricing, or slitting specifications, contact GNEE Steel to discuss your A27QG090K requirement.
Get the Full A27QG090K Datasheet & Free Grade Cross-Reference
Download the complete A27QG090K technical datasheet with a sample mill test certificate, and let our engineers cross-reference A27QG090K to your local standard (ASTM / EN / JIS / GB) at no cost - so you can qualify it confidently in your design.
Download Datasheet & Ask an Engineer →
Trusted silicon steel supply for transformer & reactor manufacturers worldwide.
FAQ
What does A27QG090K mean?
It is a high-magnetic-induction grain-oriented silicon steel: 0.27 mm thick, with maximum core loss of 0.90 W/kg (P1.7/50). The A and K are manufacturer-specific brand and coating codes.
Is A27QG090K the same as 27QG090?
They share the same core classification (0.27 mm, QG, 0.90 W/kg). The leading "A" and trailing "K" are mill-specific identifiers; confirm magnetic and coating details against the actual certificate when substituting.
What is the difference between QG (HiB) and CGO?
QG/HiB grades use secondary recrystallization to achieve higher magnetic induction (B8 ≥ 1.88 T) and lower loss than conventional CGO, making them the preferred choice for high-efficiency transformer cores.
Can A27QG090K be laser scribed?
Yes. HiB grades are commonly domain-refined (laser/plasma scribing) for additional loss reduction, though this is typically applied by the core manufacturer or on request.
What transformer types use 0.27mm HiB CRGO?
High-efficiency distribution transformers, power transformers, dry-type units, and reactors where low no-load loss is a design priority.
Disclaimer: Values are typical for the grade classification and should be verified against the mill test certificate for each coil.